Predicting a change in diagnosis from ulcerative colitis to Crohn's disease: a nested, case-control study.

BACKGROUND & AIMS: Some patients diagnosed with UC undergo a change in diagnosis to CD. Identification of predictors of a diagnostic change could potentially impact the management of patients with colonic inflammation. Our aim was to characterize clinical and serologic predictors of a change in diagnosis from UC to CD. METHODS: A nested, case-controlled study was performed to compare individuals with a change in diagnosis from UC to CD (cases) with age-matched UC and CD controls; primary analysis compared cases with UC controls. Subjects underwent chart review for clinical "red flags" identified by gastroenterologists with expertise in IBD. Serum collected at the time of database enrollment was tested for antibodies to oligomannan (anti-Saccharomyces cerevisiae), Pseudomonas fluorescens-related protein, Escherichia coli outer membrane porin C, CBir1 flagellin, and perinuclear antineutrophil cytoplasmic antibodies. RESULTS: Twenty-one cases, 52 UC controls, and 56 CD controls were assessed. Three red flags, but no serologic markers, differed between cases and UC controls. At initial colonoscopy, cases were more likely to have extensive colonic involvement than UC controls (P = .008). Multivariate regression identified non-bloody diarrhea at initial presentation (P = .01) and weight loss >10% at presentation (P = .007) as independent predictors of diagnostic change. Serologic markers did not add to the contribution of these 2 clinical factors in predicting a change in diagnosis from UC to CD. Diagnostic change was evident in 6 of 6 (100%) patients with both predictors, compared with 8 of 50 (16%) with neither of these factors (P < .0001). CONCLUSIONS: Patients with a diagnosis of UC with initial non-bloody diarrhea or weight loss have an increased likelihood of subsequent change in diagnosis to CD and might thus warrant further diagnostic work-up.

Studying the overlap between IBS and GERD: a systematic review of the literature.

Evidence points to a significant overlap between irritable bowel syndrome (IBS) and gastroesophageal reflux disease (GERD). In this study, we evaluate this overlap by conducting a systematic review of the literature. Six electronic databases from 1966 through January 2005 were screened by multiple search terms to identify all epidmiological evidence linking IBS and GERD. In addition, AGA meeting abstracts for 2003 and 2004 were also screened. All studies were validated by the authors and data extracted according to predefined criteria. As a separate search strategy, studies evaluating the prevalence of IBS and GERD in the general population were sought. These articles were obtained to compare the prevalence of IBS and GERD in the community to the degree of overlap. The search identified 997 original titles with 15 publications that fulfilled our eligibility criteria. Among the 15 studies, 7 determined the GERD maximum mean prevalence in patients already diagnosed with IBS to be 39.3% and the weighted mean 30.3%. The other 7 studies examined the prevalence of IBS in patients already diagnosed with GERD. The maximum mean prevalence of IBS in subjects with known GERD was 48.8% and the weighted mean 60.5%. Based on the prevalence of IBS (12.1%) and GERD (19.4%) in the community, the rate of IBS in the non-GERD community was calculated to be only 5.1%. There is a strong overlap between GERD and IBS that exceeds the individual presence of each condition. In the absence of GERD, IBS is relatively uncommon.