# New Updates in Chronic Constipation and Irritable Bowel Syndrome



## eric (Jul 8, 1999)

FYINew Updates in Chronic Constipation and Irritable Bowel Syndrome CME/CE"PathophysiologySymptoms of IBS are conceptualized as changes in brain-gut interactions leading to altered GI function, modulated by internal and external factors, including genetic predisposition, chronic stress, dietary intake, and infection.[51] These alterations may eventually cause disorders in mucosal immune response, intestinal motility and permeability, and visceral hypersensitivity that produce abdominal pain or discomfort and, thus, compromised bowel function.[52] Visceral hypersensitivity is one of the hallmark features of IBS.[53] This hypersensitivity is experimentally measured by balloon distension of the colon or rectum, observed as increased perception of colonic distensions and contractions, and is likely clinically manifested by increased discomfort during normal bowel activity.""With growing evidence of increased colonic mucosal immune markers, the efficacy of antibiotics for the treatment of SIBO, and of probiotics for the treatment of patients with IBS symptoms, the postulated mechanism of altered bacterial-mucosal interactions playing a role in IBS appears conceivable. Pimental and colleagues[68] presented a 2-center, randomized, placebo-controlled trial assessing the efficacy of a 10-day course of the nonabsorbable broad-spectrum antibiotic rifaximin* at a dose of 400 mg peroral thrice daily. A 7-day stool diary, questionnaires, and lactulose breath test for SIBO were administered before and after treatment. The primary efficacy end point was global improvement in IBS, with clinical responders defined as having > 50% improvement overall. Forty-three patients were randomized to rifaximin and 43 to placebo. The intention-to-treat analysis demonstrated a 37.7 Â± 5.8% overall improvement with rifaximin compared with 23.4 Â± 4.3% with placebo (P < .05). Rifaximin was also associated with a significantly higher responder rate of 37% compared with 16% for placebo. Patients with diarrhea showed a greater clinical response with rifaximin (49%) than placebo (23%), *but patients with constipation did not demonstrate such a response."*It looks like there was not a 50 percent improvement?"Two studies demonstrated evidence of the misconceptions that IBS patients have about their condition, and support the need for effective educational programs for this patient population. Interesting studies regarding the diagnostic evaluation of IBS patients were also highlighted during these meeting proceedings. An ongoing, prospective study demonstrated that although diagnostic testing uncovered abnormalities that could explain IBS symptoms in only 4% of patients, serologic screening for celiac sprue would likely be a cost-effective strategy. Another study found that using the *glucose hydrogen breath test (rather than the lactulose breath test) detected SIBO in only 11% of patients with IBS symptoms,* *a finding that is significantly lower than that reported in other studies.* Although the role of SIBO in IBS requires further study, there appears to be a subgroup of IBS patients with SIBO who benefit from treatment with the nonabsorbable broad-spectrum antibiotic rifaximin.11% is a lot less then some 80%?http://www.medscape.com/viewarticle/517739


----------

