Aim: The aim of this study was to evaluate the long-term outcome of patients with collagenous colitis 10 years after the diagnosis.
Patients and methods: In 1989/1990, 65 patients were diagnosed to have collagenous colitis. Initially and after an interval of ten years these patients were asked to complete a questionnaire including onset and duration of diarrhea, stool frequency and consistency, other gastrointestinal symptoms including weight loss, drug history, treatment response and concomitant diseases.
Results: Questionnaires from 47 patients (72.3 %) (female 40; mean age 68 years, range 41 - 95 years) were available for analysis. After a follow-up of ten years, 11 patients (23.4 %) had persistent diarrhea with no change of frequency and consistency compared to baseline. Four patients (8.5 %) showed a reduction of diarrhea frequency of at least 50 %. Diarrhea was resolved in 23 patients (48.9 %) during the follow-up period. Of those, 20 patients received anti-inflammatory treatment. After a complete resolution of diarrhea during the long-term follow-up, 9 patients (19.2 %) showed recurrence of diarrheal symptoms. None of the patients developed any malignancies of the GI-tract.
Conclusion: The long-term outcome of CC is benign with a resolution of diarrhea in up to 50 % of patients receiving anti-inflammatory treatment. About 30 % of patients may experience persistent diarrhea even 10 years after diagnosis. Our data confirm that CC is a chronic disorder with a variable course of symptoms during a long-term follow-up.