Colonoscopy may be the preferred method of screening for colorectal cancer in women.

OBJECTIVES There are limited data on the yield of colonoscopy in patients with irritable bowel syndrome (IBS). This study compared the prevalence of structural colonic lesions in patients with suspected non-constipation-predominant IBS and healthy volunteers. We also determined the yield of rectosigmoid biopsies in patients with suspected IBS. METHODS This was a prospective, case – control study conducted at three US sites. Patients with suspected non-constipation-predominant IBS (Rome II) underwent colonoscopy with rectosigmoid biopsies. Healthy persons undergoing colonoscopy for colorectal cancer screening or polyp surveillance comprised the control group. Abnormalities identified at colonoscopy were compared between suspected IBS and control groups. RESULTS In all, 466 suspected IBS patients and 451 controls were enrolled. Suspected IBS patients were significantly younger (P < 0.0001) and more frequently female (P < 0.0001) than controls. The most common lesions in suspected IBS patients were hemorrhoids (18.2%), polyps (14.6%), and diverticulosis (8.8%). Suspected IBS patients had a lower prevalence of adenomas (7.7% vs. 26.1%, P < 0.0001) and diverticulosis (8.8% vs. 21.3%, P < 0.0001) and higher prevalence of mucosal erythema or ulceration (4.9% vs. 1.8%, P < 0.01) compared with controls. Logistic regression found the between-group differences in adenoma prevalence to be robust after correction for demographic factors. The overall prevalence of microscopic colitis in suspected IBS patients was 1.5% (7/466) and 2.3% (4/171) in those ≥45 years of age. CONCLUSIONS The prevalence of structural abnormalities of the colon is no higher in suspected non-constipation IBS patients than in healthy controls. Microscopic colitis can be identified in a small proportion of persons with IBS symptoms.

Background & Aims Guidelines recommend that patients with symptoms of non-constipated inflammatory bowel syndrome (NC-IBS) undergo testing for celiac disease (CD). We evaluated the prevalence of CD antibodies and biopsy confirmed CD among patients with NC-IBS in a large US population. Methods In a study conducted at 4 sites, from 2003 to 2008, we compared data from 492 patients with symptoms of NC-IBS to 458 asymptomatic individuals who underwent colonoscopy examinations for cancer screening or polyp surveillance (controls). All participants provided blood samples for specific and non-specific CD-associated antibodies. Additionally, patients with IBS were analyzed for complete blood cell counts, metabolic factors, erythrocyte sedimentation rates, and levels of C-reactive protein and thyroid-stimulating hormone. Any subjects found to have CD-associated antibodies were offered esophagogastroduodenoscopy and duodenal biopsy analysis. Results Of patients with NC-IBS, 7.3% had abnormal results in tests for CD-associated antibodies, compared to 4.8% of controls (adjusted odds ratio=1.49; 95% confidence interval, 0.76–2.90. P=.25). Within the NC-IBS group, 6.51% had antibodies against gliadin, 1.22% against tissue transglutaminase, and 0.61% against endomysium (P>.05 vs controls for all antibodies tested). CD was confirmed in 0.41% of patients in the NC-IBS group and 0.44% of controls (P>0.99). Conclusions Although CD-associated antibodies are relatively common, the prevalence of CD among patients with NC-IBS is similar to that among controls in a large US population. These findings challenge recommendations to routinely screen patients with NC-IBS for CD. More than 7% of patients with NC-IBS had CD-associated antibodies, indicating that gluten sensitivity might mediate IBS symptoms; further studies are needed.