[Evolution and treatment response in microscopic colitis]. / Curso evolutivo y respuesta al tratamiento de las colitis microscópicas.

AIM: To study the clinical characteristics, treatment response and evolution in patients with microscopic colitis. MATERIAL AND METHODS: We performed a retrospective analysis of 24 patients (15 with collagenous colitis and 9 with lymphocytic colitis). Clinical and diagnostic features, treatment response and evolution according to the presence of maintenance therapy were evaluated. RESULTS: The mean age of the patients was 59.7 years and most were male. Nine patients took non-steroidal anti-inflammatory drugs (NSAID). No significant association was found with other drugs. Four patients presented associated rheumatological disease. Most patients presented insidious-onset diarrhea without pathological products, which was frequently associated with other symptoms (abdominal pain, bloating, weight loss, asthenia, tenesmus, and incontinence). Seven patients showed a slight increase in globular sedimentation rate. Fat in stools and radiological investigations (transit and opaque enema) were normal in patients who underwent these tests. Endoscopy revealed non-specific alterations in 42% of the patients while results were normal in the remaining patients. One patient showed clinical improvement on withdrawal of NSAIDs and 4 patients improved spontaneously. Clinical response was achieved in 7 of 13 patients treated with antimotility drugs, in 8 of 9 patients treated with salicylates, in 3 treated with oral corticoids, in 1 treated with cholestyramine and in 1 treated with topical budesonide. Nineteen patients required no maintenance therapy, 4 were administered salicylates and 1 was administered cholestyramine. After a mean follow-up of 42 months, evolution was chronic and intermittent in 14 patients and chronic and continuous in 1; 9 patients presented a single episode. No significant differences were found between patients administered maintenance therapy and those who were not or between collagenous colitis and lymphocytic colitis in the parameters analyzed. CONCLUSIONS: Microscopic colitis constitutes a group of diseases characterized by chronic diarrhea, few systemic effects and minimal radiological and/or endoscopic alterations. Evolution is characterized by recurrent episodes, with good response to treatment with cholestyramine, salicylates or corticoids when required.