Colitis evolving into ulcerative colitis

We observed the development of ulcerative colitis (UC) in a 37 year old young woman with clinical and histological features of lymphocytic colitis (LC) after a period of six years. Seven years ago, the patient was admitted to our gastroenterology unit complaining of watery diarrhoea (⩾6 stools/day). She had never smoked and she was not taking any drugs affecting gastrointestinal secretion or motility. Laboratory tests, including autoimmune antibody and upper endoscopy, were normal. Parasitological and bacteriological faecal stools were negative. Biopsies of the jejunum did not show a pattern of coeliac disease. Colonoscopy with terminal ileoscopy was macroscopically normal. Ten biopsy specimens were taken from the rectum, revealing the histological pattern of LC (intraepithelial lymphocytes 41/100 epithelial cells, inflammation in the lamina propria, and surface epithelial changes consisting of degeneration). 5-ASA therapy (2.4 g/day) was administrated for 24 weeks. Within the first two weeks of treatment the patient experienced clinical remission (⩽2 stools/day). At end of therapy the patient underwent colonoscopy and 10 biopsy specimens were taken from the rectum. At histology we observed complete regression of the inflammatory cells (intraepithelial lymphocytes ⩽10/100 epithelial cells) and restoration of the surface epithelium. In this way we obtained complete control of symptoms. Colonoscopy with biopsies of the rectum was repeated every year, confirming remission of the disease.

After six years the patient experienced abdominal pain and bloating with progressive worsening of diarrhoea. The stools became watery, sometimes bloody, and frequency was up to 8–10 times/day. She denied intake of non-steroidal anti-inflammatory drugs, ASA, or estro-progestinic therapy. Parasitological and bacteriological faecal stools were negative. Colonoscopy was performed and revealed a micro granularity of the rectal mucosa with oedema and hyperaemia, and several erosions of the left colon were noted. No other lesions were found on the remaining colon or terminal ileum. Biopsies were taken and histology showed a moderately active ulcerative colitis. Laboratory tests were consistent with an elevated white blood cell count and increased inflammatory parameters. The patient was treated with oral prednisolone and 5-ASA (4.8 g/day). Complete regression of symptoms was obtained after two weeks of treatment. The patient continues to be in remission 18 weeks after the initial diagnosis of UC. She is still receiving 2.4 g/day 5-ASA, and oral prednisolone has been discontinued, with maintenance of resolution of symptoms.

In the literature, four cases of collagenous colitis (CC) evolving into UC have been reported^1–4 and two cases that developed into Crohn’s disease.^4,5 This is the first case of LC evolving into UC. These phenomena suggest that both CC and LC could be part of a spectrum of inflammatory bowel diseases. The triggering factor in this transformation is still unknown. UC should be considered in patients with LC if they develop acute changes in their clinical course, with bloody diarrhoea and systematic features of UC.