Background-Lymphocytic colitis is characterised by chronic watery diar
rhoea with normal endoscopic or radiological findings and microscopic
evidence of pronounced infiltration of the colonic mucosa with lymphoc
ytes. Aim-To investigate the long term clinical and histological evolu
tion of the disease in a large group of patients with well characteris
ed lymphocytic colitis. Methods-Between 1986 and 1995 the histological
diagnosis of lymphocytic colitis was obtained in 35 patients; 27 of t
hese 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-T
he patients initially presented with the typical findings of lymphocyt
ic colitis. After a mean (SD) follow up of 37.8 (27.5) months, diarrho
ea 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 n
ormalisation of histology in over 80% of patients within 38 months. Co
nsidering the benign course of the disease, the potential benefit of a
ny drug treatment should be carefully weighed against its potential si
de effects.