in the clinic Irritable Bowel Syndrome Diagnosis page ITC7-2 Treatment page ITC7-8 Practice Improvement page ITC7-14 Patient Information Page page ITC7-15 CME Questions page ITC7-16 Section Editors The content of In the Clinic is drawn from the clinical information and Christine Laine, MD, MPH education resources of the American College of Physicians (ACP), including David Goldmann, MD PIER (Physicians’ Information and Education Resource) and MKSAP (Medical Knowledge and Self-Assessment Program). Annals of Internal Medicine Science Writer editors develop In the Clinic from these primary sources in collaboration with Jennifer F. Wilson the ACP’s Medical Education and Publishing Division and with the assistance of science writers and physician writers. Editorial consultants from PIER and MKSAP provide expert review of the content. Readers who are interested in these primary resources for more detail can consult http://pier.acponline.org and other resources referenced in each issue of In the Clinic. The information contained herein should never be used as a substitute for clinical judgment. © 2007 American College of Physicians Downloaded From: http://annals.org/ by McGill University, Teresa Rudkin on 04/08/2016 in the clinic rritable bowel syndrome (IBS) is a common but poorly understood dis- order that interferes with normal colon function, resulting in abdominal I pain, bloating, constipation, and diarrhea. No specific biological bio- marker, physiologic abnormality, or anatomical defect has been discovered. Psychosocial stress may exacerbate symptoms. IBS is 1 of 28 adult and 17 pediatric functional gastrointestinal disorders. These disorders are symptom-based and not explained by other pathologically defined diseases. IBS appears to be linked to motor and sensory physiology and brain–gut interaction (1). Emerging theories suggest that alteration of intestinal bacteria may also play a role in the condition. IBS affects as many as 1 in 5 U.S. adults, occurs more often in women than in men, and begins before the age of 35 in about half of all people who develop the disorder. IBS is recognized worldwide, but prevalence varies geographically. Diagnosis What symptoms should prompt a individual patient’s symptom clinician to consider IBS? pattern can change over time, it Symptoms of IBS vary from person is debatable whether symptom to person, but clinicians should pattern clearly demarcates consider IBS if abdominal discom- patients with different IBS fort or pain associated with bowel subtypes. dysfunction is present. Other symptoms that suggest IBS include Certain clinical features, often prominent gastrocolic reflex, alter- called alarm features or red flag nating constipation and diarrhea, symptoms, suggest that the diagno- and excess gas and sis is something other than IBS (2) flatulence. Gas- (see Box). Alarm features include trointestinal symp- Alarm Features That Suggest toms that wax and Possible Organic Disease weight loss, noctur- wane for more nal awakening be- Symptoms cause of gastroin- than 2 years and • Weight loss those that are exac- • Frequent nocturnal awakenings testinal symptoms, erbated by psy- due to gastrointestinal blood in the stool, chosocial stress symptoms family history of should raise suspi- • Fever colon cancer or in- cion for IBS • Blood mixed in stool flammatory bowel over other History disease, recent use diagnoses. • New onset, progressive of antibiotics, and symptoms fever. Three general pat- • Onset of symptoms after age 50 terns of bowel • Recent antibiotic use What are the symptoms are • Family history of colon cancer or accepted diagnostic 1. Drossman DA. The inflammatory bowel disease functional gastroin- common in IBS: criteria for IBS? testinal disorders and Physical Findings the Rome III process. diarrhea-predomi- • Abdominal mass History is the main Gastroenterology. nant, constipation- diagnostic tool for 2006;130:1377-90. • Stool positive for occult blood [PMID: 16678553] predominant, and • Enlarged lymph nodes IBS. There are 2 2. Longstreth GF. Irrita- mixed (alternating sets of symptom- ble bowel syndrome. Diagnosis in the diarrhea and con- based diagnostic cri- managed care era. Dig Dis Sci. stipation). Determining a patient’s teria to help discriminate IBS from 1997;42:1105-11. predominant symptom pattern can other disorders: the Manning crite- [PMID: 9201069] 3. Manning AP, Thomp- be useful in guiding management ria and the Rome criteria (Table 1). son WG, Heaton KW, because the different subgroups These criteria were developed for Morris AF. Towards positive diagnosis of respond differently to the various use in clinical studies, but can be the irritable bowel. Br Med J. 1978;2:653-4. therapeutic options. Because an helpful in clinical settings. [PMID: 698649] © 2007 American College of Physicians ITC7-2 In the Clinic Annals of Internal Medicine 3 July 2007 Downloaded From: http://annals.org/ by McGill University, Teresa Rudkin on 04/08/2016 Manning and colleagues (3) pro- recommends that clinicians base posed the first widely used IBS cri- classification of IBS symptoms as When Rome criteria have been teria in 1978 based on the symp- diarrhea-prominent; constipation- satisfied, warning symptoms toms listed in Table 1. prominent; or mixed, based on stool consistency. Rome criteria are are absent; the history and In 1989, a group of experts met in dynamic, and future studies are Rome and developed another set of physical examination suggest consensus-based criteria known as needed to confirm the validity of IBS; and the occult blood test, the Rome criteria to assist in the recent changes intended to increase diagnosis of IBS and other func- the usefulness of the criteria in re- complete blood count, and tional gastrointestinal disorders (4). search and clinical settings (1). erythrocyte sedimentation The Rome criteria, which are also When diagnostic criteria are satis- rate are normal, the risk for displayed in Table 1, were based on a broader array of symptoms than fied; warning symptoms are absent; overlooking organic disease the history and physical examina- the Manning criteria and explicitly may be as low as 1% to 3%. considered both duration and fre- tion suggest IBS; and the occult quency of symptoms. In 1999, the blood test, complete blood count same group of experts developed (CBC), and erythrocyte sedimenta- the Rome II criteria, a modified tion rate (ESR) are normal, the risk version of the earlier criteria in- for overlooking organic disease may tended to be more adaptable to be as low as 1% to 3%. Thus, ex- clinical practice (5). pert consensus is that physicians should limit evaluation to fulfill- The group released the most recent ment of the Rome or Manning version of the Rome criteria, Rome criteria if no alarm symptoms are III, in 2006. Rome III did not present. change the basic diagnostic criteria for IBS but modified the time frame Even without exclusion of alarm features, for symptoms and description of the presence of at least 3 of the 6 Manning IBS subtyping (6). Rome III speci- criteria has an average sensitivity of ap- fies that symptoms must have begun proximately 60% and specificity of approx- at least 6 months before the diag- imately 80%. The criteria’s sensitivity and nosis can be established and that specificity vary by study; however, the diag- patients have fulfilled the Rome nostic accuracy is known to be better in criteria for at least 3 months before women, younger patients, and when more IBS can be diagnosed. Rome III criteria are fulfilled (7). Table 1. Symptom Criteria for Irritable Bowel Syndrome 4. Thompson WG, Dote- wall G, Drossman DA, Rome III* et al. Irritable bowel Recurrent abdominal pain or discomfort at least 3 days per month in the past 3 months syndrome: guidelines for the diagnosis. associated with 2 or more of the following: Gastroenterol Int. 1. Improvement with defecation 1989;2:92-95. 5. Thompson WG, 2. Onset with change in frequency of stool Longstreth GF, Dross- man DA, et al. Func- 3. Onset associated with a change in the form and appearance of stool tional bowel disor- ders and functional *Criteria must be fulfilled for at least the past 3 months with symptom onset at least 6 months before abdominal pain. Gut. diagnosis. 1999;45 Suppl 2:II43- 7. [PMID: 10457044] 6. Longstreth GF, † Manning Thompson WG, Chey WD, et al. Functional Pain relief with defecation, often bowel disorders. Gas- Looser stools at pain onset, often troenterology. 2006;130:1480-91. More frequent stools at pain onset, often [PMID: 16678561] 7. Talley NJ, Phillips SF, Visible abdominal distention Melton LJ, et al. Diag- Mucus per rectum nostic value of the Manning criteria in ir- Feeling of incomplete evacuation ritable bowel syn- drome. Gut. †To establish IBS diagnosis, patient must meet 3 or more criteria. 1990;31:77-81. [PMID: 2318433] 3 July 2007 Annals of Internal Medicine In the Clinic ITC7-3 © 2007 American College of Physicians Downloaded From: http://annals.org/ by McGill University, Teresa Rudkin on 04/08/2016 Tolliver and coworkers showed that the fulfill the Rome criteria, and have Rome criteria had a positive predictive val- no alarm features, a presumptive ue of 98.5%—out of 196 patients, they ex- diagnosis of IBS can be made with- cluded 1 case of colon cancer, 1 of colitis, out endoscopy but should be and 1 of peptic ulcer (8). reevaluated depending on the Vanner and colleagues prospectively stud- course of symptoms over time. Be- ied 95 patients who met the Rome criteria cause patients with IBS have ab- and lacked red flags and found the positive normally sensitive gastrointestinal predictive value was 98% (9). tracts, they may find endoscopy more uncomfortable than do pa- Investigators conducted interviews with a large, community-based sample of U.S. tients without this condition. Rec- women diagnosed with IBS, and they tal and colonic balloon studies have found that Rome I was significantly more shown hypersensitivity of the intes- sensitive than Rome II (84% vs.