The diagnostic yield of stool pathogen studies during relapses of inflammatory bowel disease

Goals: We sought to determine the yield of stool analysis for bacterial culture, ova and parasites, and Clostridium difficile toxin in suspected relapses of inflammatory bowel disease (IBD). Background: The diagnostic yield of such stool studies has not been examined recently in the United States. Study: The medical records of consecutive IBD patients who underwent stool testing for relapses at our institution between July 1, 2000, and November 25, 2001, were abstracted for demographics, stool test results, recent antibiotic exposure, and hospitalization. Results: Fifty-four patients were evaluated during 62 relapses with 99 stool samples. Twelve stool tests were positive. C difficile accounted for the majority of positive tests (10/12). Of these, 9 (90%) were associated with antibiotic use in the prior month versus 10 (22%) in the C. difficile-negative group (P < 0.001). Hospitalization, prednisone use, or sulfasalazine use did not differ significantly with C. difficile status. Eight C. difficile-positive patients improved clinically with targeted antibiotic therapy. Two bacterial cultures (4%) were positive for Campylobacter jejuni and Plesiomonas shigelloides. Conclusion: Stool studies yielded a pathogen, mainly C. difficile, in 20% of the relapsing IBD patients. Antibiotic use was significantly associated with a positive C. difficile toxin. Toxin-positive patients improved clinically with targeted antibiotics.