Background: Collagenous colitis (CC) is a rare large bowel inflammatory disorder. The aim of this retrospective study was to analyze extra-digestive manifestations of CC, associated systemic diseases, clinical course and response to therapeutic regimens.
Patients and methods: Between 1989 and 1999, eleven patients were diagnosed as having CC, in two Departments of Internal Medicine and Gastroenterology, on the basis of usual criteria: chronic watery diarrhea, endoscopic examination showing normal findings and subepithelial collagen band thicker than 10 micrometer.
Results: Ten women and one man, age 39 to 88 years (mean: 66.6), had had their diarrhea for 1 to 240 months before diagnosis (mean: 48). Associated extra-digestive manifestations were: weight loss (3 cases out of 11), inflammatory arthralgia (4 cases), fever (2 cases), pelvispondylitis (2 cases), autoimmune thyroiditis (2 cases), and Sharp syndrome (1 cases). Laboratory abnormalities were: inflammatory syndrome (3 cases), anemia (5 cases), hypogammaglobulinemia (3 cases), and hypoalbuminemia (4 cases). Stool cultures and parasite examination were negative in all patients. Therapy used successively for CC until resolution of chronic diarrhea (uncontrolled with symptomatic treatment) was: sulfasalazine in 7 patients (beneficial (B) in 5 out of 7), 5-aminosalicylic acid in 6 (B: 2/6), corticosteroids in 2 (B: 2/2), azathioprine in 1 (B: 1/1). After a mean follow-up of 18 months (range: 1-72), resolution of CC was observed in 8 out of 11 patients.
Discussion: Mean characteristics of CC were: female predominance (91%), presence of extra-digestive manifestations (36%); mucosal inflammation with subepithelial collagen band and frequent association to rheumatic or autoimmune diseases suggest an immune basis for CC. Usefulness of systematic colon biopsies is underlined. Clinical course is often favorable with sulfasalazine and 5-aminosalicylate acid. Corticosteroids are rarely used.