Background: Lymphocytic colitis is characterised by chronic watery diarrhoea with normal endoscopic or radiological findings and microscopic evidence of pronounced infiltration of the colonic mucosa with lymphocytes.
Aim: To investigate the long term clinical and histological evolution of the disease in a large group of patients with well characterised lymphocytic colitis.
Methods: Between 1986 and 1995 the histological diagnosis of lymphocytic colitis was obtained in 35 patients; 27 of these agreed to a follow up examination. All clinical, endoscopic, and histopathological records were reviewed at that time and the patients had a second endoscopic examination with follow up biopsies.
Results: The patients initially presented with the typical findings of lymphocytic colitis. After a mean (SD) follow up of 37.8 (27.5) months, diarrhoea subsided in 25 (93%) and histological normalisation was observed in 22 (82%) of the 27 patients. Progression from lymphocytic colitis to collagenous colitis was not observed.
Conclusions: Lymphocytic colitis is characterised by a benign course with resolution of diarrhoea and normalisation of histology in over 80% of patients within 38 months. Considering the benign course of the disease, the potential benefit of any drug treatment should be carefully weighed against its potential side effects.