DDW 2013 Note: Getting a Clear Picture of the Average Symptom Pattern in IBS

Irritable bowel syndrome (IBS) is a disorder that is defined entirely in the formal diagnostic criteria (currently the Rome III criteria) by the symptoms of abdominal pain, diarrhea and/or constipation. All of these three symptoms are known to be intermittent in the disorder. However, because few studies have tracked the bowel symptoms of large groups of IBS sufferers carefully on a daily basis over extended periods of time, our knowledge about the typical episodic behavior of these symptoms has been poor, and surprisingly little has been known about to what degree the different bowel symptoms occur together or separately. How often do patients for example have constipation on days when they also have abdominal pain? And what proportion of their total days do they have bowel symptom episodes of any type? This kind of information has not been available in IBS.

Today I presented the results of a study by our UNC-Chapel Hill research team at Digestive Disease Week 2013 in Orlando which aims to give a better picture of the typical symptom episode pattern in IBS overall. We analyzed diary data from 124 adult IBS patients who met the Rome III diagnostic criteria for the disorder and had also been diagnosed by a doctor as having the disorder. These study participants tracked their every bowel movement (BM) for 90 days in a pocket-sized diary. They rated the consistency of each bowel movement on the Bristol Stool Scale (1-7 ratings with verbal and picture descriptors where 1-2 is considered constipation and 6-7 diarrhea: See more about the scale here) and transferred these ratings to a secure website each night, where they also rated global 24-hour abdominal pain (0-10 scale).

Since we wanted to study typical symptom activity in IBS, we did several things to try to ensure that the diary data in our study reflected as natural and typical IBS symptoms as possible:

  • We used a long diary recording period. IBS is a fluctuating disorder, so to capture a characteristic pattern of symptoms for each individual, we decided we would have to track the symptoms for months. We therefore decided on a three-month (90-day) diary recording.
  • We did not study patients who were coming to clinics or doctors for help, because those would be likely to have more active symptom episodes that were bringing them in at the present time. Instead, we advertized for patients who had been diagnosed with IBS through our University mass e-mail system, on various websites and also recruited participants who had signed up in a registry to participate in research studies for our Center. We then verified that they met Rome III criteria for IBS.
  • We only included in our analysis diary information from patients who reported no laxative or anti-diarrheal medication use in their diaries during their whole diary recording period, and who were on none of the IBS-specific medications, so we could be sure that we were seeing “natural” symptom patterns unaffected by bowel medications.

The patients who ended up included in our analysis dataset were predominantly female (89%), of an average age of 36.7 years, and were of all subtypes of IBS (38 IBS-D, 69 IBS-M, 16 IBS-C, and 1 IBS-U).

The first thing we had to do in order to be able to systematically analyze symptom episode patterns in the diaries was to define what constituted an episode for each kind of symptom. For pain episodes, this was easy – we used definitions that had already been established 1 by our colleagues in a different study, and which we found reasonable based on our data. For diarrhea and constipation episodes, however, no such episode definitions existed so we conducted systematic pattern analysis of bowel movements in all the diary datasets to come up with effective episode definitions. I will not describe those analyses here, for they are rather complicated and will be described in our forthcoming paper. But the episode definitions we ended up using for the three type of central symptoms in IBS was as follows:

  • A diarrhea episode is a series of at least 2 diarrhea BMs never separated by more than 1 non-diarrhea BM nor by a day without a BM.
  • A constipation episode is a series of at least 2 constipation BMs and/or one or more sequences of 3+ no-BM days, never separated by more than 1 non-constipation BM. Constipation episodes included non-BM days.
  • A pain episode is a series of one or more days of daily pain severity rated higher than 3 on a 0-10 scale

Then we analyzed the diary records of the 124 IBS patients to see how long, how frequent and how overlapping or separate episodes of different symptoms were.

What we found was that on average, diarrhea episodes lasted 2.1 days, constipation episodes 4.45 days for constipation, and pain episodes 3.1 days.

Diarrhea episodes were present on 16.2% of total diary days, constipation episodes on 22.5% and pain episodes on a whopping 44.6% of days. Interestingly, pain episode days co-occurred far more frequently with diarrhea episode days than with constipation episode days (70.5% vs. 39.1% overlap).

Amazingly to me, we found that IBS symptom episodes of any kind (that is, either pain or constipation or diarrhea or a combination of more than one of these) were on average present on nearly two-thirds of all days for this sample of patients (63.8% of days to be precise). We also found (which perhaps does not surprise anybody) that the higher the percentage of their total days the patients spend in IBS symptom episodes, the poorer are their their quality of life scores.

Since this is a lot of complicated information with a whole bunch of number, a picture is worth a thousand words, as the saying goes. So here is a pie chart representing the typical symptom episode activity of the IBS patients in our study. The whole circle represents all days for the average IBS patient, and the various slices of the pie show what percentage of total days different types symptom episodes are occurring.

Figure. Average Symptom Pattern in IBS (% of total days; based on 3-month diaries of 124 patients):


We are continuing to analyze these diary data to further understand symptom patterns and will soon be describing our findings in more detail than we did here at DDW today in our forthcoming paper. Of course there is a huge amount of variability between individuals in their symptom picture, so the figure above does not apply to all IBS patients. Nonetheless, I think it is useful to depict the symptom episode pattern overall across IBS subtypes as I have done here, so that one can get a better appreciation of the general nature of IBS symptom activity. For example, I was surprised to see how much of total days in the life of IBS patients symptom episodes are present, even though I have done research and clinical work with IBS for nearly 20 years. You cannot get that type of bird’s-eye summary view of what IBS looks like except through this kind of thorough symptom-tracking in a large number of individuals across a long period of time.

In summary, what we are finding is that the three defining symptoms of IBS all occur in distinct episodes rather than being randomly spread over time. Pain episodes are the most frequent type of symptom episode, roughly happening on average on 2 out of every 5 days in the life of the typical IBS patients, and these pain episodes tend to overlap with diarrhea episodes more commonly than with constipation episodes. On average, patients experience IBS symptom episodes on nearly 2/3 of all days. More frequent IBS episode days are associated with increased quality of life impairment.


Tu2070. Symptom Episode Patterns in Irritable Bowel Syndrome (IBS). Olafur S. Palsson, Jeffrey S. Baggish, William E. Whitehead. Center for Functional GI and Motility Disorders, University of North Carolina, Chapel Hill, NC and CSL Behring, King of Prussia, PA


1: Hellström PM, Saito YA, Bytzer P, Tack J, Mueller-Lissner S, Chang L. Characteristics of acute pain attacks in patients with irritable bowel syndrome meeting Rome III criteria. Am J Gastroenterol. 2011 Jul;106(7):1299-307. doi: 10.1038/ajg.2011.78. Epub 2011 Mar 29. PubMed PMID: 21448146.

DDW 2013 Note: Unusually High Rate of Joint Hypermobility Syndrome in Patients Diagnosed with Functional GI Disorders

Joint Hypermobility Syndrome is a connective tissue disorder characterized by overly elastic skin and “loose joints” that bend too much (joint hyperflexibility)1. It is a fairly common condition (it may be present in as many as 15% of the population) that has genetic underpinnings and runs in families, but it is generally benign and typically goes undiagnosed because in many people it does not produce any troublesome symptoms (this should not be confused with a more serious but rare condition with somewhat similar connective tissue abnormalities, called Ehlers-Danlos Syndrome). Because the joints are so loose in people with Joint Hypermobility Syndrome, those individuals are prone to joint dislocations, sprains and painful strain around their joints. When symptoms do occur, these are therefore often pain in joints – fingers, elbows, knees and fingers. In recent years, a couple of studies in the United Kingdom have indicated that gastrointestinal symptoms are associated with this syndrome. One study found that patients with this connective tissue syndrome had greater constipation and rectal evacuation problems than other people2, and another found higher than expected prevalence of this syndrome in a retrospective survey of patients with unexplained GI symptoms who had been seen in a neurogastroenterology clinic3.

Yesterday, Sunday May 19, the same team of researchers from the United Kingdom who published those previous observations presented a new well-designed study at Digestive Disease Week 2013 in Orlando that gives a clearer and more definite picture of the association of Joint Hypermobility Syndrome with gastrointestinal problems. They evaluated 694 newly referred patients in a row who were coming to gastroenterology (GI) clinics, and used the so-called Brighton Diagnostic Criteria to assess whether they had Joint Hypermobility Syndrome. They also evaluated 92 patients in other clinics coming for non-GI problems for comparison. After the GI patients had been evaluated and diagnosed by the GI doctors they were seeing, the researchers compared the prevalence of Joint Hypermobility Syndrome in patients with functional GI disorders, organic GI disorders (like inflammatory bowel disease or cancer), and in the non-GI control patients. They excluded GI patients who were diagnosed with reflux disease (GERD) from analysis for a clearer picture, as GERD can be considered a mixture of functional and organic disease.

The results were interesting and thought-provoking. The rate of Joint Hypermobility Syndrome was significantly higher in patients who GI doctors diagnosed as having functional GI disorders (40.5%) than in either patients found to have organic GI disease (26.9%) or non-GI comparison patients (25%). This strongly suggests that a subset of patients who are seen by gastroenterologists and diagnosed as having functional GI disorders like IBS or functional dyspepsia actually have a verifiable organic problem – a connective tissue abnormality – that either contributes significantly to their symptoms or might even cause them altogether, in which case they are really being mis-classified as functional GI patients. These very interesting results from a well-designed study definitely warrant future examination in research on functional GI patients in my opinion, especially since the Brighton Diagnostic Criteria can be easily incorporated in questionnaire evaluation of these patients.

So how do you know if you have Joint Hypermobility Syndrome? Some signs of it are1 (1) that you are (or ever have been able to) put your palms flat on the floor standing up with your legs straight; (2) that you can (or ever could) touch your forearm with your thumb (on the same side, of course!); (3) have been known to be “double jointed” or able to contort yourself into unusual shapes to amuse and amaze your friends, or (4) often dislocated your joints as a child. And if you are a professional contortionist, it’s probably a fairly sure bet that you have this syndrome!


Asma Fikree, Rubina Aktar, Lucy E. Glasgow, Katherine V. Gillespie, Adam D. Farmer, Rodney Grahame, Joan K. Morris, Charles H. Knowles, Qasim Aziz. The Association Between Functional Gastrointestinal Disorders and the Joint Hypermobility Syndrome – Connective Tissue Is the Missing Link!   Wingate Institute of Neurogastroenterology; Blizard Institute of Cell and Molecular Science, Barts and the London School of Medicine and Dentistry, Queen Mary University London, London, United Kingdom; National Centre for Bowel Research and Surgical Innovation, Blizard Institute of Cell and Molecular Science, Barts and the London School of Medicine and Dentistry, Queen Mary University London, London, United Kingdom; Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine and Dentistry, Queen Mary University London, London, United Kingdom; Rheumatology, University College Hospital, London, United Kingdom; Gastroenterology, Shrewsbury and Telford NHS Trust, London, United Kingdom


1. Simpson MR. J Am Osteopath Assoc September 1, 2006 vol. 106 no. 9 531-536. Available in full online here: http://www.jaoa.org/content/106/9/531.full

2. Mohammed SD, Lunniss PJ, Zarate N, Farmer AD, Grahame R, Aziz Q, Scott SM.
Joint hypermobility and rectal evacuatory dysfunction: an etiological link in
abnormal connective tissue? Neurogastroenterol Motil. 2010 Oct;22(10):1085-e283.
doi: 10.1111/j.1365-2982.2010.01562.x. Epub 2010 Jul 5. PubMed PMID: 20618831.

3. Zarate N, Farmer AD, Grahame R, Mohammed SD, Knowles CH, Scott SM, Aziz Q.
Unexplained gastrointestinal symptoms and joint hypermobility: is connective
tissue the missing link? Neurogastroenterol Motil. 2010 Mar;22(3):252-e78. doi:
10.1111/j.1365-2982.2009.01421.x. Epub 2009 Oct 15. PubMed PMID: 19840271.

DDW 2013 Note: Yes, You Can Get IBS and Functional Dyspepsia from Bad Drinking Water

In December of 2010, a fire broke out in an apartment building in Belgium. As firefighters struggled to contain the blaze, they used sewer water to fight the fire. In the process, they accidentally connected that water source to the main community  water supply. Sewer water, containing among other things infectious organisms like norovirus, Giardia and Campylobacter, was pumped into the drinking water pipes and spread quickly throughout the water supply of this town of about 18.000 people. Within 24 hours, a lot of people were seeking help for acute gastrointestinal illness, and it was clear that a major outbreak of GI infection had occurred.

It is now well known from many studies that a subset of people who become sick from food poisoning or contaminated water develop chronic functional gastrointestinal disorders as a result  – irritable bowel syndrome (IBS) and functional dyspepsia (FD). Researchers are always looking for natural experiments or accidents like this water contamination to study how infections turn into chronic gastrointestinal disorders and who develops such problems and who does not. In this case Belgian gastroenterology researchers in Leuven, which happens to be a mere half-hour drive from where this outbreak occurred, were quick to descend upon the unfortunate town in order to get baseline data from the local residents and start following their health over time.

Today at Digestive Disease Week 2013 in Orlando, those researchers presented their findings of their study of the long-term effects of this massive but brief exposure to contaminated drinking water.

In the study, they asked all the residents of the affected town to complete questionnaires on gastrointestinal symptoms they had before, during and after outbreak, and also about  their psychological symptoms and other characteristics. These questionnaires were completed 0-3 months after the outbreak.  They also asked the subjects to complete such questionnaires again a year after the outbreak to evaluate the long-term effects on GI symptoms. A total of 1377 people completed the questionnaires, but data from children younger than eighteen and from all people who reported that they had GI symptoms consistent with IBS or functional dyspepsia before the outbreak were eliminated from analysis. This left 1028 questionnaire sets to be analyzed. It turned out that 30% of the subjects had become sick with infectious gastroenteritis within 2 weeks of the contamination. When those individuals were surveyed a year later, 15.6% of them were found to have IBS and 19% had functional dyspepsia, according to Rome III diagnostic criteria (remember, none of these people had these disorders before the gastroenteritis outbreak). Interestingly, a fairly significant number of individuals in the other 70% of the survey sample — the ones who were exposed to the contaminated water as well but did not have immediate GI problems — were also found to have IBS (6.5%) and FD (12%) after a year (much higher rates of new incidence of these disorders than one would typically expect in the general population). The investigators found that of all the individual characteristics that they assessed in the study, being of younger age and having higher somatization score at the time of the outbreak (that is, already having a lot of non-gastrointestinal body symptoms) were factors that predicted greater likelihood of developing long-term IBS or functional dyspepsia symptoms after exposure to the contamination. Having diarrhea symptoms for several days after exposure was also a risk factor for meeting diagnostic criteria for IBS a year later.

This study is a very nice addition to the research knowledge base on post-infectious IBS and post-infectious functional dyspepsia. I particularly liked that the researchers studied functional dyspepsia and IBS in parallel, for this allows direct comparison of the relative risk of developing each of those disorders long-term from infection. Another valuable aspect of the study is that the contamination here was a broad cocktail of common infectious organisms that can cause GI problems. This makes the findings more generalizable, for it shows us the substantial long-term health risk associated with drinking unclean water for even a relatively short period of time. The risk factors identified as causing people to be more likely to develop long-term post-infectious gastrointestinal diseases in this research are the same as have been found in multiple previous studies1 so this work confirms once again that younger adults are more vulnerable, and that not recovering quickly from the initial gastroenteritis bowel distress and being prone to having a lot of body symptoms are all factors make people more likely to develop chronic functonal GI disorders from infection.

I found two additional aspects of the findings from this study particularly interesting: The first was to see that people can develop long-term functional GI disorders as a result of drinking contaminated water without having any acute GI symptoms soon after the exposure to clue you in that they have even been infected at all. And the second noteworthy observation was that exposure to water contamination mostly resulted in either IBS or functional dyspepsia a year later, but few people developed both disorders: There was only 17% overlap according to my conversation with the principal author, Sander van Wanrooij, at DDW today.


Su2031. Postinfectious Irritable Bowel Syndrome and Functional Dyspepsia Following an Outbreak of Tap Water Contamination. Sander van Wanrooij, Mira M. Wouters, Stephanie Mondelaers, Laura van Gerven, Annick de Vries, Pedro J. Gomez-Pinilla, Guy E. Boeckxstaen. University Hospital and University of Leuven, Belgium


1. Ghoshal UC, Ranjan P. Post-infectious irritable bowel syndrome: the past, the
present and the future. J Gastroenterol Hepatol. 2011 Apr;26 Suppl 3:94-101. doi:
10.1111/j.1440-1746.2011.06643.x. Review. PubMed PMID: 21443719.

DDW 2013 Note: What Keeps Patients and Doctors from Addressing Fecal Incontinence?

Fecal incontinence (accidental loss of liquid or solid stool), which will be abbreviated FI here, is a sensitive and difficult health problem that is present in about 9% of the overall adult population1. It becomes more common with age, rising in prevalence from about 3% of people aged 20-30 to more than 15% in those 70 years and older1. When FI happens frequently (2.7% of U.S. adults have FI episodes once a week or more) it can have a major adverse impact on people’s lives if untreated, leading to substantial problems in areas such as mobility, work, social life, and self-esteem.

FI is a highly treatable problem.  Anorectal biofeedback2 and sacral nerve stimulation3,4 are both treatments that seem to help get rid of the problem entirely in half of cases and also significantly improve about half of the remaining cases where complete continence is not achieved. Furthermore, a much simpler treatment that consists of systematic use of pelvic floor exercises results in improvement in FI in roughly half of cases as well5. But even though these methods are highly effective, they actually benefit far fewer individuals than one might hope, because most cases of fecal incontinence never even come to the attention of healthcare providers and no treatment can therefore be offered. Surveys indicate that 70 to 90 percent of individuals who have FI have not talked to their doctor about it6. Although it is understandable that fecal incontinence can be hard to talk about, there are important and often severe adverse personal consequences that can be prevented only by addressing the problem it in healthcare encounters. Finding ways to systematically overcome the barriers that keep fecal incontinence a largely hidden and unaddressed health problem could improve the lives of millions of adults who now suffer the consequences without any help. The first step is to understand what keep patients and doctors from addressing the problem.

In a poster presentation at Digestive Disease Week 2013 in Orlando yesterday, Saturday May 18, investigators in our UNC Center for Functional GI & Motility Disorders reported the findings of a study of 124 adults who were identified as having FI by asking them about it when they came to clinic visits in a variety of clinics in the UNC Healthcare System (primary care, urogynecolory, gastroenterology and geriatrics). Eighty-eight of these individuals had consulted with  doctors about their FI problem  (those can be called FI consulters) but 36 had not done so (i.e., they were FI non-consulters). The patients were surveyed through written questionnaires to evaluate the severity and frequency of their FI and its impact on their lives, and they were also interviewed over the phone about their experiences and views on interacting with healthcare providers about it and outlook on treatment for the problem.

Some of the key findings were:

    • The  severity and frequency of fecal incontinence episodes was not different between FI consulters and  non-consulters (as measured on the validated Fecal Incontinence Severity Index)
    • Most (77.1%) FI  non-consulters stated that doctors need to ask directly about  incontinence. However, half of them also indicated a preference for being asked about it through a questionnaire.
    • The only aspects of quality of life impact of fecal incontinence (measured on a validated FI-QOL scale) that was different between consulters and non-consulters was depression/self-esteem impact, which was greater in consulters
    • Among FI non-consulters, 44.4% reported that they believed that there was no effective treatment available for fecal incontinence, versus only 15.6% of FI consulters.
    • The three most common reasons FI non-consulters gave for not discussing their FI problem with their doctor were not thinking it was serious enough (57.1%), thinking it was just a normal part of aging rather than a medical problem (45.7%), and embarrassment (37.1%).

The investigators also interviewed 11 physicians in the clinics where the patients were recruited, to get a sense of the reasons why doctors fail to screen routinely for fecal incontinence by asking their patients about it. Only 4 of the 11 doctors reported that they did not screen for fecal incontinence, and they mostly stated lack of time in patient visits as a reason not to do so. They were also more likely than doctors who screened to believe that fecal incontinence is a rare condition.

This study gives a fairly clear idea of what keeps so many patients and doctors from addressing FI in clinical encounters, and also provides some insights about what is needed to overcome those barriers. The results indicate that more than half of the patients who do not report FI to their doctors simply do not regard their FI as a significant problem. However, many other patients are held back from reporting FI to doctors by embarrassment or because they wrongly do not believe it is treatable. It would seem that the patients in the latter category need to be helped to overcome the hindrances to getting help for FI by making education about effective treatments for FI widely available and by screening for FI in a way that minimizes embarrassment and doctor time burden. It is noteworthy that individuals with FI who have not consulted doctors mostly do feel that doctors and clinics should ask them about it directly and many of them would prefer that this be done via a questionnaire. Routine use of a few simple questions (or even a single one) on paper to screen for this problem in all visits to major healthcare service settings like primary care and geriatric clinics would enable healthcare providers to reliably identify and offer care for fecal incontinence in most adults who make any use of healthcare.


Sa2036. “Fecal Incontinence: What Determines Which Patients Consult Physicians and Which Physicians Screen?” Lalitha Kunduru, Sung M. Kim, Steve Heymen, William E. Whitehead. Center for Functional GI and Motility Disorders, University of North Carolina, Chapel Hill, NC.


1. Whitehead WE, Borrud L, Goode PS, Meikle S, Mueller ER, Tuteja A, Weidner A, Weinstein M, Ye W. Fecal incontinence in US adults: epidemiology and risk factors. Gastroenterol 2009;137:512-517.

2. Heymen S, Scarlett Y, Jones K, Ringel Y, Drossman D, Whitehead WE. Randomized controlled trial shows biofeedback to be superior to pelvic floor exercises for fecal incontinence. Dis Colon Rectum 2009;52:1730-1737.

3. Tjandra JJ, Chan MK, Yeh CH, Murray-Green C. Sacral Nerve Stimulation is more Effective than Optimal Medical Therapy for Severe Fecal Incontinence: A Randomized, Controlled Study. Dis Colon Rectum 2008;51:494-502.

4. Wexner SD, Coller JA, Devroede G, Hull T, McCallum R, Chan M, Ayscue JM, Shobeiri AS, Margolin D, England M, Kaufman H, Snape WJ, Mutlu E, Chua H, Pettit P, Nagle D, Madoff RD, Lerew DR, Mellgren A. Sacral nerve stimulation for fecal incontinence: results of a 120-patient prospective multicenter study. Ann Surg 2010;251:441-449.

5. Norton C, Chelvanayagam S, Wilson-Barnett J, Redfern S, Kamm MA. Randomized controlled trial of biofeedback for fecal incontinence. Gastroenterology. 2003 Nov;125(5):1320-9.

6. Dunivan GC, Heymen S, Palsson OS, von Korff M, Turner MJ, Melville JL, Whitehead WE. Fecal incontinence in primary care: prevalence, diagnosis, and
health care utilization. Am J Obstet Gynecol. 2010 May;202(5):493.e1-6. doi: 10.1016/j.ajog.2010.01.018. PubMed PMID: 20223447.

DDW 2013 Note: Self-perceived Poor Health in IBS is Mostly Due to Other Things Than Bowel Symptoms

Disease and illness are two different phenomena that overlap to a widely varying degree1. Disease is a problem with the structure or function of an organ or organ system in the body. Illness, in contrast, refers to the behavioral, emotional and cognitive reactions or consequences of that disease (for example, the behavior of lying in bed, feeling lousy and considering oneself to be unhealthy are all very common illness consequences of having the viral disease influenza). It is of course, possible to have disease without any illness if there are no troublesome symptoms. And conversely, it is possible for people to feel ill without any physical disease, for example because of psychological upset, physical over-exertion, or extreme fatigue. However, most disease produces some physical symptoms that in turn result in some degree of illness. How much a given amount of disease results in the patient being ill and perceiving himself/herself to be in poor health varies a lot from person to person, though. And in chronic diseases, where physical symptoms are present frequently over time, the degree to which people feel in poor health and have illness with their disease is of major importance, for it will likely affect their entire life outlook and functioning.

When I was the Director of a Behavioral Medicine Clinic at Eastern Virginia Medical School, where we treated a large number individuals with IBS, we had this standard questions on our health history intake form: “How would you rate your overall health?”. The were four answer options: Poor, Fair, Good, and Excellent. I found it very intriguing to see that sometimes we would get IBS patients with severe bowel symptoms who rated their overall health on this four-point scale as “Excellent” at the very time that they were coming to us seeking help for a disease that was causing them considerable trouble and suffering. And conversely, IBS patients in our clinic with only mild bowel symptoms would sometimes rate their health as “Poor” even though they did not report any other serious medical problems. In short, it became clear to me that self-perceived health of IBS patients was commonly not very closely tied to the status of the bowel symptoms that define the disorder. Many people who work a lot with IBS or other chronic illness have noted similar discrepancy between disease severity and sense of health, but what other factors than disease determines how much illness is associated with a disease has generally been poorly understood.

Today at Digestive Disease Week 2013 in Orlando, Lackner and colleagues presented an interesting analysis of this in IBS that sheds some light on this matter. They studied 235 IBS patients who had no other gastrointestinal disease. The patients completed a whole battery of questionnaires to measure their self-rated health (using a 5-point rating scale) along with psychological symptoms, general (non-gastrointestinal) physical symptoms, quality-of-life impact of the IBS symptoms, and social functioning. The investigators found that the actual severity of IBS symptoms (measured on the validated IBS Severity Scale) and how much the IBS affected life functioning only predicted self-ratings of poor health to a very minor degree (even though it was statistically significant in this large sample). Instead, a whole group of other factors that had nothing to do with bowel symptoms were more substantially associated with poor health, including fatigue, the amount of general non-gastrointestinal body symptoms or non-GI diagnoses, negative social interactions, and feeling anxious or depressed. Because so many different variables correlated with poor self-rated health, the investigators simplified their explanatory model by picking the statistically strongest contributing factors, and found in the end that three separate variables — fatigue, somatization (that is, the amount of general non-GI symptoms) and negative social interactions — added together in predicting self-ratings of poor health, and added together to produce a sense of poor health. Together, these three variables explained a total of 35% of the variability in health self-ratings.

Assuming that the three key variables identified in this study to be associated with poor self-perceived health hold up in analysis of other patient samples, these observations have clear implications for treatment of IBS (and perhaps for other chronic disease conditions as well). They confirm that IBS bowel symptoms actually play a relatively minor role in patients’ personal sense of health, and point instead to specific other aspects of IBS functioning that should be addressed to improve this important aspect of personal well-being. It seems likely that some fine-tuning or shift in emphasis in the adjunctive psychological and educational interventions that are widely used to help IBS patients could accomplish this, because the tools for addressing each of these three variables that seem to contribute substantially to a sense of poor health already exist: Cognitive behavioral therapy is ideal for addressing and neutralizing the impact of negative social interactions; hypnosis treatment reduces somatization in IBS (and cognitive behavioral therapy does so as well to some extent); and teaching patients methods that improve sleep (something that in my opinion far too often neglected in IBS, which is a disorder notorious for impaired sleep) is already done in some places and could be done much more routinely and systematically.

What is missing now, of course — even in spite of these new insights — is to explain what accounts for the rest of the variability in how healthy or ill IBS patients feel (more than half of it is still unexplained). Further research will hopefully add those missing pieces in the future, but this is a great start and a valuable addition to the research literature.


Sa1326 “Psychosocial Predictors of Self Ratings of Health in Moderate to Severe IBS Patients: What’s Involved in Feeling Healthy Besides the Severity of GI Symptoms?” Jeffrey M. Lackner, Gregory D. Gudleski, Laurie Keefer, Darren M. Brenner, Travis J Stewart, Gary Iacobucci, Rebecca Firth, Camille Simonetti, Christopher Radziwon, Susan S. Krasner, Michael D. Sitrin, Leonard A. Katz, Sarah Quinton and Elyse Sklar. University at Buffalo, SUNY, Buffalo, NY; Northwestern University, Chicago; Wayne State University, Detroit, MI

Presented at Digestive Disease Week in San Diego, May 18, 2013.


Helman CG. Disease versus illness in general practice. J R Coll Gen Pract. 1981 September; 31(230): 548–552


Jeffrey Lackner, Ph.D., Associate Professor of Medicine at the University of Buffalo, SUNY, and Principal Author of this Study Report, in the Poster Session at Digestive Disease Week 2013 Today.

IBS: A Truly Global Phenomenon

Irritable bowel syndrome (IBS) is a health problem that people sometimes assume to be primarily a Western phenomenon. This may be because until recently most of the popular discussion of IBS, and most of the scientific investigation of it as well, has taken place in Western countries. It is now clear from research conducted in all corners of the world, however, that IBS is a truly global human disorder occurring at high rates in every population of the planet. Three articles1,2,3 just published in the scientific literature provide new broad insights into IBS as a worldwide phenomenon.

The first of these papers is a meta-analysis (meaning summary analysis of all qualifying published studies) by Lovell and Ford in England1. It gives an enlightening planet-wide view of IBS, based on pooled findings from published studies on 80 different populations all over the world with a combined total of over a quarter of a million people suveyed.

There are certainly some problems with trying to draw overall conclusions from so many different studies conducted in numerous different countries. For example, how subjects were recruited varied greatly between studies. It is also unknown how comparable the translations and understandability of symptom questions were across the many different languages and cultures. Both of these variable may influence how IBS looks from country to country. The largest problem with coming to firm conclusions about the global manifestation of IBS, though, is almost certainly the fact that the diagnostic criteria used to detect it have evolved over the past decades. The oldest studies in Lovell and Ford’s summary analysis used the so-called Manning criteria (meeting 3 or more of those), which are the predecessors of the more recent Rome criteria, and those oldest criteria clearly inflate prevalence rates compared to Rome criteria. The Rome diagnostic criteria themselves have in turn also morphed over time – from Rome I to Rome II to Rome III, each version using questions that assess IBS somewhat differently and setting a bit different standards for what can be considered to be IBS. Fortunately, this single largest bias in estimating prevalence probably washes out to a large extent when all studies for each region are combined and averaged. In spite of such methodological variations that may limit precision in findings, some broad overall conclusions can definitely be drawn from this large body of studies summarized by Lovell and Ford about IBS as a world-wide disorder. These include the following:

1. IBS is very common in every part of the world. The overall prevalence in the 80 study populations was 11.2% of the general population, with no region of the world showing lower prevalence than 7% (see figure below).

2. There is great variability in prevalence rates between different regions of the world. The region with the highest rate of IBS, South America (21% IBS), has three times the rate of the region with the lowest prevalence, which is Southeast Asia with only 7% IBS rate. I created the below figure based on the pooled region data presented in Lovell and Ford’s article for easy at-a-glance comparison of IBS rates in different regions of the world. The reasons for the dramatic differences in IBS prevalence between parts of the world that are evident from this figure are unknown at the present time.

Figure: IBS prevalence in the regions of the world (based on pooled data from 81 studies reported by Lovell and Ford1):


3. IBS is clearly a female-predominant disorder, although it is common in both sexes. Overall, IBS is found world-wide in 14.0% of women and 8.9% of men. There are some countries like India, Pakistan and China where this female predominance is not as clearly seen. In contrast, the U.S. has even more striking sex difference, with 2 to 1 female/male ratio in community surveys and as high as 4 to 1 in specialty clinics (the latter amplified ratio almost certainly due to the fact that women are on average far more likely than men to go to doctors in the U.S.).

4. IBS is somewhat less common in older individuals. The prevalence across all these international studies was 11.0% for individuals in their 20s and 30s, 9.6% for those in their 40s, 7.8% in the 50s, and 7.3% for people age sixty and older.

The other two articles that have been very recently published on this topic are a consensus statement published by the World Gastroenterology Organisation Summit Task Force on IBS2, and a report on the 2012 joint Rome Foundation and World Gastroentrology expert meeting on global IBS2. These articles provide an overall picture generally consistent with the four main global characteristics of IBS listed above, but add some nuances and details. The former of these articles2 points out, for example, that studies on the effects of IBS on quality of life indicate that impact on people’s lives is similar and substantial in different parts of the world; that all over the world, care for individuals with IBS constitutes a large proportion of the workload of gastroenterologists; and that associations with psychosocial features such as anxiety, depression and abuse history, as well as high overlap with certain other gastrointestinal and non-GI medical conditions (such as functional dyspepsia, fibromyalgia and chronic pelvic pain), seem to characterize IBS all over the world. The latter article3 summarizes discussion among experts about cultural, linguistic and geographic differences in IBS assessment and care and the various obstacles that these factors pose to the study of the phenomenon of IBS across countries and world-wide.

What these three articles published within the past few months collectively demonstrate, is that IBS is a vast health problem for the human population in general and that GI experts from around the world are increasingly joining forces to understand the disorder on a global scale. If the prevalence of 11.2% world-wide is approximately correct, as calculated by Lovell and Ford1, it can be estimated that a staggering 578 million individuals 15 yeas and older are suffering from this disorder right now (given the current world population of about 7 billion people and 26.3% of that population being under age 154). Many of these IBS sufferers will have relatively mild symptoms. But even if only a minority of them are severely affected by tthe disorder, their numbers are so high that IBS is likely to have significant impact on societies everywhere. This is especially likely considering that most IBS patients live with family members or are in intimate relationships, and many are employed in settings where they work in close collaboration with co-workers. So apart from the substantial demand that so many people ill with IBS place on healthcare resources of different nations, the various functional impairments caused by the bowel symptoms are also likely to affect both IBS sufferers and multiple people in their most immediate social network, causing significant overall effects in lost work productivity and impairment in human well-being across the globe.


1: Lovell RM, Ford AC. Global prevalence of and risk factors for irritable bowel syndrome: a meta-analysis. Clin Gastroenterol Hepatol. 2012 Jul;10(7):712-721. PubMed PMID: 22426087.

2: Quigley EM et al. A global perspective on irritable bowel syndrome: a consensus statement of the World Gastroenterology Organisation Summit Task Force on irritable bowel syndrome. J Clin Gastroenterol. 2012
May-Jun;46(5):356-66. PubMed PMID: 22499071.

3: Sperber AD, Drossman DA, Quigley EM. The global perspective on irritable bowel syndrome: a rome foundation-world gastroenterology organisation symposium. Am J Gastroenterol. 2012 Nov;107(11):1602-9. PubMed PMID: 23160283.

4: http://en.wikipedia.org/wiki/World_population

DDW 2012 Note: New Insights Into the Sleeping Problems of Individuals With IBS

Sleeping difficulties are a common complaint in the general adult population, but are even more frequently reported by individuals with irritable bowel syndrome. For example, our UNC research team found in a large HMO survey1 of 662 IBS patients several years ago that two-thirds (67%) of them reported having had difficulty sleeping more than once in the past month. This was a significantly higher percentage than found for the healthy comparison subjects (although 49% of those also experienced recurrent sleeping difficulties).

Evidence has been accumulating in research for a couple of decades that the quality of sleep is poorer in IBS patients than in other individuals, and that nights of poor sleep result in worsened bowel symptoms on the days that follow for patients with the disorder2,3. However, those studies have relied on patients’ self-ratings of sleep quality. A study reported by Patel and colleagues on Saturday May 19 at Digestive Disease Week 2012 in San Diego improves on the prior research by using an objective measure of sleep — a wrist-mounted actigraph device that measures body motions and can distinguish between sleeping and waking with high sensitivity.

The researchers measured the sleeping and waking patterns of 20 IBS subjects with the actigraph for a seven-day period, and compared them to those of 23 healthy controls. Subjects also kept daily logs of bowel pain severity and distress, consistency of bowel movements (on the Bristol Stool Scale) and intensity of other bowel symptoms (bloating, gas, urgency, and mucus) during this seven-day test phase.

The results showed that the IBS patients actually slept significantly longer than controls on the average (8.1 vs. 6.9 hours). However, the IBS subjects woke up more times during the night and had shorter average undisturbed sleep periods. Shorter periods of uninterrupted sleep and greater number of awakenings during the night were both found to be statistically associated with more abdominal pain and more GI distress the following day in the IBS patients (but were not associated with other symptoms like bloating or hard or loose stools). The number of awakenings during the night was also associated with worse quality-of-life scores and more gut-focused anxiety in the IBS group.

This study confirms in a more solid way than done before that individuals with IBS do indeed sleep more poorly than other individuals, with more awakenings and shorter spans of uninterrupted sleep on the average, and that this results in significant worsening of their bowel symptoms. But what causes this poor sleep in IBS? Interestingly, the researchers asked the IBS patients why they woke up during the night. Most typically, the patients complained of waking up because of non-gastrointestinal pain (like back pain), or because of needing to urinate. Although it is hard to know how accurately those self-reports reflect the real reasons for awakenings (people probably do not always realize why they find themselves awake at night), it nonetheless suggests the intriguing possibility that non-gastrointestinal somatic symptoms, which are well known from many studies to be unusally prevalent in IBS (symptoms such as muscle pain and frequent need to urinate) are interfering with sleep, which then in turn disturbs gut function and worsens gastrointestinal symptoms.


“Disturbed Sleep Worsens IBS Pain Symptoms: an Effect of Gastrointestinal (GI) Specific Anxiety?” Ami Patel, Benjamin Cassell, Mrudula Kumar, C. Prakash Gyawali, Gregory S. Sayuk. Division of Gastroenterology, Washington University School of Medicine, Saint Louis, MO

Presented at Digestive Disease Week in San Diego, May 19, 2012.


1. Palsson OS, Jones KR, Turner MJ, Drossman DA, Whitehead WE.  Impact of somatization and comorbid medical conditions on health care utilization, disability, and quality of life in irritable bowel syndrome (IBS). Gastroenterology 2002, 122 (Suppl 1): A501-502.

2. Jarrett M, Heitkemper M, Cain KC, Burr RL, Hertig V. Sleep disturbance
influences gastrointestinal symptoms in women with irritable bowel syndrome. Dig
Dis Sci. 2000 May;45(5):952-9. PubMed PMID: 10795760

3. Goldsmith G, Levin JS. Effect of sleep quality on symptoms of irritable bowel
syndrome. Dig Dis Sci. 1993 Oct;38(10):1809-14. PubMed PMID: 8404401