Collagenous colitis as the presenting feature of biopsy-defined celiac disease

Prior case reports have linked celiac disease with collagenous colitis, but serological and retrospective pathologic survey studies of small intestinal biopsies have produced conflicting results.

In this report, consecutive patients with chronic diarrhea and the initial finding of collagenous colitis were evaluated to determine if occult celiac disease was also present. All 36 patients with no exclusions were offered upper endoscopy and biopsies. If the changes of untreated celiac disease were detected in the small intestinal biopsies, then a gluten-free diet was instituted. Diet response was based on resolution of diarrhea and normalization of repeated small intestinal biopsies.

Eight patients, or over 20%, had severely abnormal small bowel biopsy changes characteristic of untreated celiac disease. In some, lymphocytic or collagenous gastritis were also detected with or without celiac disease. All 8 patients were treated with a gluten-free diet alone and, in all, diarrhea improved and small intestinal biopsies normalized. In 5, however, repeated colonic biopsies showed persistent collagen deposits. Autoimmune thyroid disease or neoplastic diseases, like lymphoma known to be associated with celiac disease were also noted in this cohort with collagenous colitis, often in the absence of celiac disease.

This study indicates that collagenous colitis may be the presenting clinical and pathologic feature of celiac disease. Diagnosis of collagenous colitis should lead the clinician to consider exclusion of underlying occult celiac disease.