Persistence of mucosal abnormality in ulcerative colitis.

The mechanism by which mucosal change is produced in ulcerative colitis is obscure. Once an attack of the disease has occurred, there is a tendency for the condition to persist or to relapse, and perhaps correlated with this is the fact that the mucosa may remain abnormal in the absence of active clinical disease. Truelove and Richards (1956) pointed out that more than 50% of patients in clinical remission had abnormal sigmoidoscopic and histological findings, which could be severe. Dick and Grayson (1961) noted similar findings. Matts (1961), in a study of the value of rectal biopsy in ulcerative colitis, examined 126 patients. All those who had active (or 'semi-active') disease showed histological abnormality, but in 47 of the patients in whom the disease was quiescent, 37 (79 %) had an abnormal mucosa histologically. It is not recorded for how long the disease had been quiescent in these patients. No systematic study to ascertain the proportion of patients in whom the mucosal abnormality persists, and whether a persisting change bears any relation to the duration of freedom from symptoms or the duration of the previous illness, has been reported. It would clearly be of interest and of importance to know how often, once a patient has had an attack of this disease, the colonic mucosa returns to normal, if indeed it ever does.