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The Tincture of Time and Irritable Bowel Syndrome Symptoms
GASTROENTEROLOGY 2011;140:1680 –1688
SELECTED SUMMARIES Gary R. Lichtenstein, Section Editor
STAFF OF CONTRIBUTORS Faten Aberra, Philadelphia, PA Nuzhat A. Ahmad, Philadelphia, PA Hans-Dieter Allescher, GermischPartenkirchen, Germany Jordi Bruix, Barcelona, Spain Lin Chang, Los Angeles, CA William Chey, Ann Arbor, MI Tsutomu Chiba, Kyoto, Japan Massimo Colombo, Milan, Italy Sheila Crowe, Charlottesville, VA
Marcia Cruz-Correa, San Juan, PR Jason Dominitz, Seattle, WA James Farrell, Los Angeles, CA Lauren B. Gerson, Stanford, CA W. Ray Kim, Rochester, MN George Lau, Hong Kong, China Josep M. Llovet, New York, NY Peter Mannon, Birmingham, AL Julian Panes, Barcelona, Spain Raoul Poupon, Paris, France
THE TINCTURE OF TIME AND IRRITABLE BOWEL SYNDROME SYMPTOMS Olafsdottir LB, Gudjonsson H, Jonsdottir HH, et al. (Division of Gastroenterology, Landspitali University Hospital, Reykjavik and Social Science Research Institute, University of Iceland, Reykjavik, Iceland). Stability of the irritable bowel syndrome and subgroups as measured by three diagnostic criteria: a 10-year follow-up study. Aliment Pharmacol Ther 2010;32:670 – 680. Irritable bowel syndrome (IBS) remains a prevalent and significant disorder in the United States, affecting between 5% and 20% of the population and compromising approximately a quarter of outpatient Gastroenterology consultations (Gastroenterology 2002;123:2108 –2131). Outside the United States, a lower IBS prevalence (3%– 5%) has been reported, either owing to differences in criteria used to classify the condition or true differences in prevalence rates (Gastroenterol Clin Biol 2004;28:554 – 561; Eur J Gastroenterol Hepatol 2007;19:441– 447; Neurogastroenterol Motil 2005;17:207–211). Prior studies have reported symptom prevalence according to the Manning, Rome II, or Rome III criteria. The Manning criteria, published in 1978 (Br Med J 1978; 2:653– 640) allowed for a diagnosis of IBS if ⱖ3 criteria were met, including abdominal pain, relief of abdominal pain with defecation, increased stool frequency with abdominal pain, looser stools with pain, mucus in stools, and/or feeling of incomplete evacuation. The criteria were able to discriminate IBS from organic disease with a sensitivity of 58% and specificity of 74% and IBS from all non-IBS gastrointestinal disease with a sensitivity of 42%, and specificity of 85% (Gut 1990;31:77– 81). The Rome II criteria, issued in 1999, stated that IBS was present if symptoms were present for ⱖ12 weeks in duration (not required to be consecutive) of the preceding 12 months. IBS was considered to be present in the setting of abdominal pain if 2 of 3 features were present, including
Eamonn Quigley, Cork, Ireland Shiv K. Sarin, New Delhi, India Shamita B. Shah, Stanford, CA Nathan Subramaniam, Brisbane, Australia George Triadafilopoulos, Stanford, CA Kenneth K. Wang, Rochester, MN Thomas D. Wang, Ann Arbor, MI Alastair J. M. Watson, Norwich, UK Stefan Zeuzem, Frankfurt, Germany
pain relief with defecation, and/or onset associated with change in frequency of stool, and/or onset associated with change in stool appearance (Gut 1999;45:1143– 1147). The Rome III criteria (Gastroenterology 2006;130: 1377–1390) stated that the onset of gastrointestinal symptoms should begin ⱖ6 months before clinical presentation and the diagnostic criteria should be fulfilled for at least 3 days per month in the last 3 months. IBS was defined as recurrent abdominal pain or discomfort in association with ⱖ2 of the following features, including improvement with defecation, onset associated with change in stool frequency, and onset associated with change in appearance of stool. Patients were further defined into 4 subgroups of IBS classified by predominance of constipation (IBS-C; defined as hard or lumpy stools ⱖ25% of the time), diarrhea (IBS-D; defined as loose or water stools ⱖ25% of the time), both (mixed subtype or IBD-M, defined as IBS-D and IBS-C ⬎25% of the time) or un-subtyped (neither IBS-C nor IBS-D). A common question among IBS patients is whether their symptoms will worsen, remain the same, or subside over time. The duration and severity of symptoms in IBS patients can change depending on a variety of factors, such as dietary consumption, environmental factors including stress and/or anxiety, and the presence of other aggravating factors including bacterial overgrowth syndrome and/or acute gastroenteritis. The purpose of this retrospective study was to compare the stability of IBS symptoms according to the Manning, Rome II and Rome III criteria over a 10-year period in Iceland. Subjects from the study were chosen from a random population study performed in Iceland in 1996 involving 2000 subjects ages 18 –75 years of age with equal distribution of gender and age in each age group. Subjects were contacted again in 2006, and 300 additional new individuals aged 18 –27 years were added who were randomly selected from the National Registry. The Bowel Disease Questionnaire (Mayo Clin Proc 1990;65:1456 – 1479) was translated from English into Icelandic and
May 2011
modified for the study data collection. Responses from the 1996 and 2006 surveys were matched for each subject to determine changes for 6 categories including IBS Rome, IBS Manning, IBS self-report (subjects were asked whether or not they thought they had IBS), functional dyspepsia, frequent abdominal pain, or no symptoms. Symptoms were characterized into 6 categories including stable, increased, decreased, new onset, becoming asymptomatic, or none of those categories. Mortality data were identified in 2006 from the National Registry of Iceland. The authors reported response rates of 67% (1336/ 2000) in 1996 and 68% in 2006 (799/1180). Drop out from 1996 included 81 deceased subjects, 70 persons who could not be traced, and 5 who could not respond owing to older age. IBS was more common in women (67% compared with 53% of the IBS-negative cohort in 1996 and 69% vs 52% in 2006, both P ⬍ .001) and in younger patients (mean age 40 years in 1996 and 49 years in 2006 compared with 44 years and 54 years without IBS; P ⬍ .0001). Compared with patients without IBS, patients with the disorder were more likely to be unemployed and to require sick leave from work. Patients with IBS were more likely to report gastrointestinal pain during childhood and the presence of any abdominal operation (including appendectomy, cholecystectomy) and report heartburn and/or functional dyspepsia symptoms compared with patients without IBS. Visits to health care providers were more frequent in the IBS group as well. Regarding development or change in IBS over the 10-year time period, 12.5% developed IBS according to the Manning criteria (n ⫽ 674), 8% in the self-reported group (n ⫽ 621), and 9% via the Rome III criteria (n ⫽ 749). IBS symptoms were retained in 19%, 8%, and 4%, respectively, and lost in 12%, 8.5%, and 6% of the cohorts. IBS symptoms never developed over the time period in 56% of the Manning cohort, 75% of the self-reported group, and 81% of the Rome III– based cohort. When the 6 descriptive categories were applied to the cohort, 39% of the Rome III group remained stable compared with 37% of the Manning cohort and 12% of the self-reported group. Symptoms increased in 17% of the Manning group, and 34% of the self-report subjects. Overall, 12% of the entire cohort remained stable, 11% noted symptomatic increase, 10% decrease in symptoms, 14% developed new symptoms, 14% became asymptomatic, and 40% reported no symptoms in 1996 or 2006. According to the Rome III criteria, the IBS-D subtype was the most prevalent group for the 1996 and 2006 time points. The prevalence of IBS-D increased from 41% in 1996 to 50% in 2006, while the IBS-C subtype decreased from 24% to 11%. Comment. According to this study in Iceland, the prevalence of IBS varied from 13% using the Rome III criteria to 32% with the Manning criteria at the time of the 1996 assessment. The authors noted that the prevalence was
SELECTED SUMMARIES
1681
greater among younger female patients and decreased up to age 75 years, but then increased in the age group from 76 to 85 years. Although there was no change in prevalence over time using the Manning or self-report criteria, the prevalence using Rome III increased from 10% to 13% from 1996 to 2006, and this increase was limited primarily to women aged 26 –55 with IBS-D. Overall, the authors found that stability of symptoms was greatest according to Manning and Rome III criteria. Over the study duration, similar proportions of patients developed or lost IBS symptoms according to the Manning criteria and self-report groups, but more subjects developed new IBS symptoms according to the Rome III criteria. The overall prevalence rates for IBS seem to be similar to other published studies in the literature in addition to the published rates for stability of symptoms. This study adds to the current literature by comparing prevalence, stability, and regression rates for IBS using Manning, Rome III, and self-reported IBS criteria. The study results suggest that the Manning criteria were associated with higher rates of symptom retention and regression, but that a higher percentage of patients never developed IBS symptoms when the Rome III criteria were applied compared with the Manning criteria. There have been multiple prior studies reporting change in IBS symptoms over time. In a populationbased study in Sweden, 1290 individuals were sampled via postal questionnaire, and 144 (12.5%) of the subjects responding to the survey reported IBS symptoms at baseline. (Gastroenterology 1995;109:671– 680). There was no change in prevalence rates for IBS symptoms 1 year later in 130 subjects. In a 2004 study performed in Spain assessing 209 subjects with IBS classified by Rome II criteria, interviews were conducted monthly for a 2-month period. Of the subjects, 61% were classified as having the same IBS subtypes on each assessment. Only 46% of IBS-D and 51% of IBS-C patients remained in the same subtype, with a tendency to shift to the IBS-M subtype over time (Am J Gastroenterol 2004;99:113– 1121). In a 1-year follow-up study of 517 subjects with IBS in Spain (Aliment Pharmacol Ther 2007:25;323–332) diary assessments occurred 5 times during the year using the Rome II criteria (n ⫽ 400 at the 1-year follow-up). Over the period of the year, 19%–25% of subjects changed from abnormal to normal bowel habit patterns. Changes from IBS-C or IBS-D to IBS-M occurred in 13%–17% of the cohort over time, whereas only 3%– 6% changed from IBS-D to IBS-C or vice versa. More than 50% of subjects with ⱖ3 diary assessments remained in the same IBS subtype when comparing the diary entry for month 1 to months 4, 7, and 10. Overall, 34% of 415 subjects who had ⬎3 diary assessments maintained the same IBS subtype throughout the entire study period. Female gender was associated with change in stool pattern with an odds ratio of 2.65 (95% confidence interval [CI], 1.1– 6.2)
1682
SELECTED SUMMARIES
In a meta-analysis of 14 published studies in 2004 (Aliment Pharmacol Ther 2004;19:861– 870), 2%–18% of patients developed worsening symptoms over the time frame of 6 months to 6 years of follow-up assessment. Symptoms remained unchanged in 30%–50% of the cohort. Approximately one third of IBS patients reported disappearance of their symptoms over a mean follow-up period of 2 years. A subsequent 12-year Mayo Clinic follow-up study using the Bowel Disease Questionnaire followed 1365 patients with functional disorders who completed 2 symptom assessments between 1998 and 2003. The prevalence of IBS symptoms did not change significantly from the baseline assessment (8.3%; 95% CI, 7.5%–9.2%) to the final survey (11.4%; 95% CI, 9.9%–12.9%; Gastroenterology 2007;133:799 – 8070). Similar to other studies, the prevalence of IBS-D increased over time (from 3.6% [95% CI, 3%– 4.2%] to 4.9% [95% CI, 3.8 – 6.0]), whereas those for IBS-C (2.7% and 2.4%) and IBS-M (1.3% and 1.2%) remained stable over time. The development of new IBS symptoms occurred in 16% of 195 subjects who did not report these symptoms at baseline and was higher for IBS-D (4.2%) compared with IBS-C (1.6%) and IBS-M (1.3%). Of 158 subjects with IBS at baseline, 87 (55%) did not report any symptoms at the final assessment. Subjects in either IBS-C or IBS-D were more likely to lose their symptoms compared with IBS-M. There were no subjects with IBS-C who transitioned into IBS-D or vice versa. Similar to other studies, females were more likely to report increased symptoms over time (odds ratio, 9.7; 95% CI, 5.2–18.2) or to develop new symptoms (odds ratio, 2.8; 95% CI, 1.6 –5.0). Finally, in a cohort of patients who developed postinfectious IBS, follow-up assessments were performed at 8 years to determine resolution of symptoms using Rome I criteria (Gut 2010;59:605– 611). Enrolled subjects were part of the Walkerton Health Study that followed the long-term effects of a large outbreak of gastroenteritis related to a municipal water contamination in May 2000. Patients who enrolled in 2002/2003 and returned for assessment in 2008 were eligible for an irritable bowel cohort study cohort if they had no prior history of IBS. Of the original 4561 WHS participants, 1166 of the 2451 (47%) who returned for the 8-year assessment were enrolled into the IBS study. The prevalence of IBS symptoms decreased from 28% at 2 to 3 years after the outbreak to 15% after 8 years, but remained significantly increased compared with controls without acute gastroenteritis (odds ratio, 3.12; 95% CI, 2–5). Risk factors for the presence of IBS at the follow-up period included female gender, younger age, presence of anxiety and/or depression, and fever or weight loss during the acute illness. In this study, the prevalence of IBS subtypes were not stable over time. Fewer than 20% of patients with IBS-C or IBS-D remained in these subtypes over the follow-up period.
GASTROENTEROLOGY Vol. 140, No. 5
Applying the results of these studies to clinical practice, the gastroenterologist can expect that approximately 30%– 40% of the IBS patients will remain within the same subtype of IBS over time and experience similar symptom frequency. Patients with IBS-C and IBS-D may transition into IBS-M over time, but it will be unlikely that patients with IBS-C will transition into patients with IBS-D. Approximately one third of patients can expect resolution of symptoms over time, although this rate may be lower among patients with postinfectious IBS. Symptom resolution can be expected to be lower in patients with IBS-M and in female subjects. The results of these outcome studies should help the practicing gastroenterologist determine appropriate management strategies for patients with this challenging clinical disorder. LAUREN B. GERSON Division of Gastroenterology and Hepatology Stanford University Stanford, California
BIOFEEDBACK TRAINING FOR DYSSYNERGIC DEFECATION: AN APPROACH WHOSE TIME HAS COME? Rao SSC, Valestin J, Brown CK, et al. (Department of Gastroenterology, University of Iowa Hospitals and Clinics, Iowa City, Iowa). Long-term efficacy of biofeedback therapy for dyssynergic defecation: randomized controlled trial. Am J Gastroenterol 2010;105:890 – 896. Rao et al set out to assess the long-term efficacy of biofeedback training as a treatment for dyssynergic defecation. The current trial was a randomized, partially blinded, placebo-controlled trial. The investigators studied 52 patients with chronic constipation who (1) had failed routine constipation management after 1 year, (2) fulfilled Rome II criteria for functional constipation, and (3) exhibited dyssynergic defecation (as defined by a dyssynergic pattern of defecation, with either prolonged difficulty (⬎1 minute) expelling a 50-mL, water-filled balloon or a prolonged delay in colonic transit time (characterized by ⬎20% marker retention). The main exclusion criteria included evidence of a structural, metabolic, or pharmacologic cause for their constipation; a history of previous gastrointestinal, spinal, or pelvic surgeries; a history of rectal prolapse, anal fissure, or specific neurologic diseases associated with constipation; or a history of severe cardiac or renal disease. Pregnant females were not eligible. Randomization was accomplished using a permuted blocks method, and subjects were randomized to 1 of 2 groups: Biofeedback or standard treatment. Each group received 3 months of therapy. Outcomes were assessed 12 months after initiation of treatment. Standard care consisted of an initial visit, where subjects were given advice
SELECTED SUMMARIES Gary R. Lichtenstein, Section Editor
STAFF OF CONTRIBUTORS Faten Aberra, Philadelphia, PA Nuzhat A. Ahmad, Philadelphia, PA Hans-Dieter Allescher, GermischPartenkirchen, Germany Jordi Bruix, Barcelona, Spain Lin Chang, Los Angeles, CA William Chey, Ann Arbor, MI Tsutomu Chiba, Kyoto, Japan Massimo Colombo, Milan, Italy Sheila Crowe, Charlottesville, VA
Marcia Cruz-Correa, San Juan, PR Jason Dominitz, Seattle, WA James Farrell, Los Angeles, CA Lauren B. Gerson, Stanford, CA W. Ray Kim, Rochester, MN George Lau, Hong Kong, China Josep M. Llovet, New York, NY Peter Mannon, Birmingham, AL Julian Panes, Barcelona, Spain Raoul Poupon, Paris, France
THE TINCTURE OF TIME AND IRRITABLE BOWEL SYNDROME SYMPTOMS Olafsdottir LB, Gudjonsson H, Jonsdottir HH, et al. (Division of Gastroenterology, Landspitali University Hospital, Reykjavik and Social Science Research Institute, University of Iceland, Reykjavik, Iceland). Stability of the irritable bowel syndrome and subgroups as measured by three diagnostic criteria: a 10-year follow-up study. Aliment Pharmacol Ther 2010;32:670 – 680. Irritable bowel syndrome (IBS) remains a prevalent and significant disorder in the United States, affecting between 5% and 20% of the population and compromising approximately a quarter of outpatient Gastroenterology consultations (Gastroenterology 2002;123:2108 –2131). Outside the United States, a lower IBS prevalence (3%– 5%) has been reported, either owing to differences in criteria used to classify the condition or true differences in prevalence rates (Gastroenterol Clin Biol 2004;28:554 – 561; Eur J Gastroenterol Hepatol 2007;19:441– 447; Neurogastroenterol Motil 2005;17:207–211). Prior studies have reported symptom prevalence according to the Manning, Rome II, or Rome III criteria. The Manning criteria, published in 1978 (Br Med J 1978; 2:653– 640) allowed for a diagnosis of IBS if ⱖ3 criteria were met, including abdominal pain, relief of abdominal pain with defecation, increased stool frequency with abdominal pain, looser stools with pain, mucus in stools, and/or feeling of incomplete evacuation. The criteria were able to discriminate IBS from organic disease with a sensitivity of 58% and specificity of 74% and IBS from all non-IBS gastrointestinal disease with a sensitivity of 42%, and specificity of 85% (Gut 1990;31:77– 81). The Rome II criteria, issued in 1999, stated that IBS was present if symptoms were present for ⱖ12 weeks in duration (not required to be consecutive) of the preceding 12 months. IBS was considered to be present in the setting of abdominal pain if 2 of 3 features were present, including
Eamonn Quigley, Cork, Ireland Shiv K. Sarin, New Delhi, India Shamita B. Shah, Stanford, CA Nathan Subramaniam, Brisbane, Australia George Triadafilopoulos, Stanford, CA Kenneth K. Wang, Rochester, MN Thomas D. Wang, Ann Arbor, MI Alastair J. M. Watson, Norwich, UK Stefan Zeuzem, Frankfurt, Germany
pain relief with defecation, and/or onset associated with change in frequency of stool, and/or onset associated with change in stool appearance (Gut 1999;45:1143– 1147). The Rome III criteria (Gastroenterology 2006;130: 1377–1390) stated that the onset of gastrointestinal symptoms should begin ⱖ6 months before clinical presentation and the diagnostic criteria should be fulfilled for at least 3 days per month in the last 3 months. IBS was defined as recurrent abdominal pain or discomfort in association with ⱖ2 of the following features, including improvement with defecation, onset associated with change in stool frequency, and onset associated with change in appearance of stool. Patients were further defined into 4 subgroups of IBS classified by predominance of constipation (IBS-C; defined as hard or lumpy stools ⱖ25% of the time), diarrhea (IBS-D; defined as loose or water stools ⱖ25% of the time), both (mixed subtype or IBD-M, defined as IBS-D and IBS-C ⬎25% of the time) or un-subtyped (neither IBS-C nor IBS-D). A common question among IBS patients is whether their symptoms will worsen, remain the same, or subside over time. The duration and severity of symptoms in IBS patients can change depending on a variety of factors, such as dietary consumption, environmental factors including stress and/or anxiety, and the presence of other aggravating factors including bacterial overgrowth syndrome and/or acute gastroenteritis. The purpose of this retrospective study was to compare the stability of IBS symptoms according to the Manning, Rome II and Rome III criteria over a 10-year period in Iceland. Subjects from the study were chosen from a random population study performed in Iceland in 1996 involving 2000 subjects ages 18 –75 years of age with equal distribution of gender and age in each age group. Subjects were contacted again in 2006, and 300 additional new individuals aged 18 –27 years were added who were randomly selected from the National Registry. The Bowel Disease Questionnaire (Mayo Clin Proc 1990;65:1456 – 1479) was translated from English into Icelandic and
May 2011
modified for the study data collection. Responses from the 1996 and 2006 surveys were matched for each subject to determine changes for 6 categories including IBS Rome, IBS Manning, IBS self-report (subjects were asked whether or not they thought they had IBS), functional dyspepsia, frequent abdominal pain, or no symptoms. Symptoms were characterized into 6 categories including stable, increased, decreased, new onset, becoming asymptomatic, or none of those categories. Mortality data were identified in 2006 from the National Registry of Iceland. The authors reported response rates of 67% (1336/ 2000) in 1996 and 68% in 2006 (799/1180). Drop out from 1996 included 81 deceased subjects, 70 persons who could not be traced, and 5 who could not respond owing to older age. IBS was more common in women (67% compared with 53% of the IBS-negative cohort in 1996 and 69% vs 52% in 2006, both P ⬍ .001) and in younger patients (mean age 40 years in 1996 and 49 years in 2006 compared with 44 years and 54 years without IBS; P ⬍ .0001). Compared with patients without IBS, patients with the disorder were more likely to be unemployed and to require sick leave from work. Patients with IBS were more likely to report gastrointestinal pain during childhood and the presence of any abdominal operation (including appendectomy, cholecystectomy) and report heartburn and/or functional dyspepsia symptoms compared with patients without IBS. Visits to health care providers were more frequent in the IBS group as well. Regarding development or change in IBS over the 10-year time period, 12.5% developed IBS according to the Manning criteria (n ⫽ 674), 8% in the self-reported group (n ⫽ 621), and 9% via the Rome III criteria (n ⫽ 749). IBS symptoms were retained in 19%, 8%, and 4%, respectively, and lost in 12%, 8.5%, and 6% of the cohorts. IBS symptoms never developed over the time period in 56% of the Manning cohort, 75% of the self-reported group, and 81% of the Rome III– based cohort. When the 6 descriptive categories were applied to the cohort, 39% of the Rome III group remained stable compared with 37% of the Manning cohort and 12% of the self-reported group. Symptoms increased in 17% of the Manning group, and 34% of the self-report subjects. Overall, 12% of the entire cohort remained stable, 11% noted symptomatic increase, 10% decrease in symptoms, 14% developed new symptoms, 14% became asymptomatic, and 40% reported no symptoms in 1996 or 2006. According to the Rome III criteria, the IBS-D subtype was the most prevalent group for the 1996 and 2006 time points. The prevalence of IBS-D increased from 41% in 1996 to 50% in 2006, while the IBS-C subtype decreased from 24% to 11%. Comment. According to this study in Iceland, the prevalence of IBS varied from 13% using the Rome III criteria to 32% with the Manning criteria at the time of the 1996 assessment. The authors noted that the prevalence was
SELECTED SUMMARIES
1681
greater among younger female patients and decreased up to age 75 years, but then increased in the age group from 76 to 85 years. Although there was no change in prevalence over time using the Manning or self-report criteria, the prevalence using Rome III increased from 10% to 13% from 1996 to 2006, and this increase was limited primarily to women aged 26 –55 with IBS-D. Overall, the authors found that stability of symptoms was greatest according to Manning and Rome III criteria. Over the study duration, similar proportions of patients developed or lost IBS symptoms according to the Manning criteria and self-report groups, but more subjects developed new IBS symptoms according to the Rome III criteria. The overall prevalence rates for IBS seem to be similar to other published studies in the literature in addition to the published rates for stability of symptoms. This study adds to the current literature by comparing prevalence, stability, and regression rates for IBS using Manning, Rome III, and self-reported IBS criteria. The study results suggest that the Manning criteria were associated with higher rates of symptom retention and regression, but that a higher percentage of patients never developed IBS symptoms when the Rome III criteria were applied compared with the Manning criteria. There have been multiple prior studies reporting change in IBS symptoms over time. In a populationbased study in Sweden, 1290 individuals were sampled via postal questionnaire, and 144 (12.5%) of the subjects responding to the survey reported IBS symptoms at baseline. (Gastroenterology 1995;109:671– 680). There was no change in prevalence rates for IBS symptoms 1 year later in 130 subjects. In a 2004 study performed in Spain assessing 209 subjects with IBS classified by Rome II criteria, interviews were conducted monthly for a 2-month period. Of the subjects, 61% were classified as having the same IBS subtypes on each assessment. Only 46% of IBS-D and 51% of IBS-C patients remained in the same subtype, with a tendency to shift to the IBS-M subtype over time (Am J Gastroenterol 2004;99:113– 1121). In a 1-year follow-up study of 517 subjects with IBS in Spain (Aliment Pharmacol Ther 2007:25;323–332) diary assessments occurred 5 times during the year using the Rome II criteria (n ⫽ 400 at the 1-year follow-up). Over the period of the year, 19%–25% of subjects changed from abnormal to normal bowel habit patterns. Changes from IBS-C or IBS-D to IBS-M occurred in 13%–17% of the cohort over time, whereas only 3%– 6% changed from IBS-D to IBS-C or vice versa. More than 50% of subjects with ⱖ3 diary assessments remained in the same IBS subtype when comparing the diary entry for month 1 to months 4, 7, and 10. Overall, 34% of 415 subjects who had ⬎3 diary assessments maintained the same IBS subtype throughout the entire study period. Female gender was associated with change in stool pattern with an odds ratio of 2.65 (95% confidence interval [CI], 1.1– 6.2)
1682
SELECTED SUMMARIES
In a meta-analysis of 14 published studies in 2004 (Aliment Pharmacol Ther 2004;19:861– 870), 2%–18% of patients developed worsening symptoms over the time frame of 6 months to 6 years of follow-up assessment. Symptoms remained unchanged in 30%–50% of the cohort. Approximately one third of IBS patients reported disappearance of their symptoms over a mean follow-up period of 2 years. A subsequent 12-year Mayo Clinic follow-up study using the Bowel Disease Questionnaire followed 1365 patients with functional disorders who completed 2 symptom assessments between 1998 and 2003. The prevalence of IBS symptoms did not change significantly from the baseline assessment (8.3%; 95% CI, 7.5%–9.2%) to the final survey (11.4%; 95% CI, 9.9%–12.9%; Gastroenterology 2007;133:799 – 8070). Similar to other studies, the prevalence of IBS-D increased over time (from 3.6% [95% CI, 3%– 4.2%] to 4.9% [95% CI, 3.8 – 6.0]), whereas those for IBS-C (2.7% and 2.4%) and IBS-M (1.3% and 1.2%) remained stable over time. The development of new IBS symptoms occurred in 16% of 195 subjects who did not report these symptoms at baseline and was higher for IBS-D (4.2%) compared with IBS-C (1.6%) and IBS-M (1.3%). Of 158 subjects with IBS at baseline, 87 (55%) did not report any symptoms at the final assessment. Subjects in either IBS-C or IBS-D were more likely to lose their symptoms compared with IBS-M. There were no subjects with IBS-C who transitioned into IBS-D or vice versa. Similar to other studies, females were more likely to report increased symptoms over time (odds ratio, 9.7; 95% CI, 5.2–18.2) or to develop new symptoms (odds ratio, 2.8; 95% CI, 1.6 –5.0). Finally, in a cohort of patients who developed postinfectious IBS, follow-up assessments were performed at 8 years to determine resolution of symptoms using Rome I criteria (Gut 2010;59:605– 611). Enrolled subjects were part of the Walkerton Health Study that followed the long-term effects of a large outbreak of gastroenteritis related to a municipal water contamination in May 2000. Patients who enrolled in 2002/2003 and returned for assessment in 2008 were eligible for an irritable bowel cohort study cohort if they had no prior history of IBS. Of the original 4561 WHS participants, 1166 of the 2451 (47%) who returned for the 8-year assessment were enrolled into the IBS study. The prevalence of IBS symptoms decreased from 28% at 2 to 3 years after the outbreak to 15% after 8 years, but remained significantly increased compared with controls without acute gastroenteritis (odds ratio, 3.12; 95% CI, 2–5). Risk factors for the presence of IBS at the follow-up period included female gender, younger age, presence of anxiety and/or depression, and fever or weight loss during the acute illness. In this study, the prevalence of IBS subtypes were not stable over time. Fewer than 20% of patients with IBS-C or IBS-D remained in these subtypes over the follow-up period.
GASTROENTEROLOGY Vol. 140, No. 5
Applying the results of these studies to clinical practice, the gastroenterologist can expect that approximately 30%– 40% of the IBS patients will remain within the same subtype of IBS over time and experience similar symptom frequency. Patients with IBS-C and IBS-D may transition into IBS-M over time, but it will be unlikely that patients with IBS-C will transition into patients with IBS-D. Approximately one third of patients can expect resolution of symptoms over time, although this rate may be lower among patients with postinfectious IBS. Symptom resolution can be expected to be lower in patients with IBS-M and in female subjects. The results of these outcome studies should help the practicing gastroenterologist determine appropriate management strategies for patients with this challenging clinical disorder. LAUREN B. GERSON Division of Gastroenterology and Hepatology Stanford University Stanford, California
BIOFEEDBACK TRAINING FOR DYSSYNERGIC DEFECATION: AN APPROACH WHOSE TIME HAS COME? Rao SSC, Valestin J, Brown CK, et al. (Department of Gastroenterology, University of Iowa Hospitals and Clinics, Iowa City, Iowa). Long-term efficacy of biofeedback therapy for dyssynergic defecation: randomized controlled trial. Am J Gastroenterol 2010;105:890 – 896. Rao et al set out to assess the long-term efficacy of biofeedback training as a treatment for dyssynergic defecation. The current trial was a randomized, partially blinded, placebo-controlled trial. The investigators studied 52 patients with chronic constipation who (1) had failed routine constipation management after 1 year, (2) fulfilled Rome II criteria for functional constipation, and (3) exhibited dyssynergic defecation (as defined by a dyssynergic pattern of defecation, with either prolonged difficulty (⬎1 minute) expelling a 50-mL, water-filled balloon or a prolonged delay in colonic transit time (characterized by ⬎20% marker retention). The main exclusion criteria included evidence of a structural, metabolic, or pharmacologic cause for their constipation; a history of previous gastrointestinal, spinal, or pelvic surgeries; a history of rectal prolapse, anal fissure, or specific neurologic diseases associated with constipation; or a history of severe cardiac or renal disease. Pregnant females were not eligible. Randomization was accomplished using a permuted blocks method, and subjects were randomized to 1 of 2 groups: Biofeedback or standard treatment. Each group received 3 months of therapy. Outcomes were assessed 12 months after initiation of treatment. Standard care consisted of an initial visit, where subjects were given advice