Rectal and colonic mucosal biopsy findings and faeces, sigmoidoscopy, and histopathological correlation in amoebiasis and other colitis.

It is rather surprising that despite the ease of obtaining a rectal biopsy and considerable experience of this technique which exist in the routine diagnosis of neoplastic lesions in the rectum, it is only over the last two decades that its application in inflammatory lesions of the colon and rectum has become popular. As amoebiasis is very common in Madras, it had become a necessity to exclude it in all cases presenting with bowel disturbances and vague dyspeptic states, particularly if associated with hepatomegaly. Further, amoebiasis coexists or complicates other colonic or rectal lesions. The various methods available for establishing the diagnosis of amoebiasis have been the demonstration of (a) the vegetative form of Entamoeba histolytica in the faeces, or rectal swab, or scrapings from ulcer or aspirated material from suspected sites or in tissues obtained at biopsy; (b) the cystic form of E. histolytica in faeces; (c) the demonstration of rectal and colonic lesions on sigmoidoscopy; (d) the complementfixation test; (e) fluorescent microscopy, and, (f) the clinical impression and response to antiamoebic treatment. Juniper (1962) observed that 18 out of 22 patients in whom ulcers were seen sigmoidoscopically showed diagnostic trophozoites in mucosal biopsy specimens. Doxiades and Yiotsas (1965) observed amoeba by light microscopy not only in the walls of ulcers as noted by others, but also in 37% of rectal and colonic mucosal biopsy material from regions which were apparently normal at sigmoidoscopy. If this could be corroborated we feel that it will be a very useful procedure in establishing a definite diagnosis in such cases of colitis, non-ulcer dyspepsias, hepatomegaly, and pleuro-pulmonary lesions which are sometimes treated as arnoebic in aetiology purely on clinical impressions.