Background: Microscopic colitis has been increasingly diagnosed in recent years with improved awareness amongst endoscopists that biopsies must be taken from macroscopically normal colons, in patients presenting with diarrhoea. The two main variants are lymphocytic colitis (LC) and collagenous colitis (CC). Aim: To evaluate the long term natural history and follow-up of patients diagnosed with lymphocytic colitis in a University teaching hospital.
Methods: This is an ongoing retrospective study. Patients diagnosed with lymphocytic colitis were identified from the histopathology department database in our instituation. Clinical details were obtained through a combination of chart review and follow up telephone interview.
Results: To date 60 cases of LC have been identified. The female to male ratio 2.1: 1. Median age at diagnosis 55 years. 92% of patients presented with diarrhoea. The median follow-up period was 5.9 years. 20/60 (33.3%) of patients had 1 colonoscopic and histologic follow-up at a median of 2.6 years from time of diagnosis. Of these, 8/20 (40%) had normal histology. Of these 20 patients 12 were on treatment. 8/60 (13.3%) of patients undewrwent a second colonoscopy at a median of 6.6 years from diagnosis and biopsy was normal in 7/8 cases. At diagnosis, CRP was raised in 8 patients (13.3%), normal in 16 patients (26.6%) and not available in 60% of the patients. 26 (43%) patients were smokers, 9 (15%) patients had coeliac disease and 38 (63%) patients had thyroid disease. 18 (30%) of patients were on NSAIDs, 16 (27%) on statins and 27 (45%) were on a PPI. 33 patients had regular follow (55%) with minimal symptoms. No follow up data is currently available for 27 (45%) of patients but is being sought.
Conclusions: LC colitis is commonly associated with other autoimmune conditions. In those patients in whom follow up histology was available, there was complete histologic remission in 40%. A significant proportion of patients had no follow-up/did not seek follow-up which raises the possiblity that their symptoms were not problematic. Further follow-up of patients with microscopic colitis is necessary to gain better insight into the natural history of this condition.