Cytology of colonic mucosal secretions from patients with non-specific haemorrhagic proctocolitis in complete clinical remission.

As a rule the diagnosis of non-specific haemorrhagic proctocolitis is easy when the case history is characteristic and when the patients can be examined during an active phase of the disease. In the majority of such cases sigmoidoscopy will reveal typical changes, as will radiological examination if a substantial part of the colon is involved in the pathological process. The diagnosis can, however, present considerable difficulty if the colon symptoms are slight and uncharacteristic-for example, comprising only rectal bleeding in connexion with constipation. Furthermore, the patients may be quite free of symptoms at the time of examination. In this situation it is desirable to reduce the diagnostic threshold by the introduction of microscopical criteria. Of the different techniques devised for this purpose the suctionbiopsy method of Truelove, Horler, and Richards (1955) has been the most popular. We have described a simple replica method (Anthonisen and Riis, 1961) which has proved a valuable tool in the diagnosis of proctosigmoidal disease.