1.   Colonic carcinoma was found in three patients.

2.   The comparative infrequency of colonic carcinoma that we have found compared with other studies is probably because of the differences in the age distribution of the populations studied.

3.   Simple scoring of symptoms and signs is unhelpful in indicating the diagnosis, though a clinical suspicion of colonic carcinoma has reasonable sensitivity and specificity.

4.   Moreover, the same group of xenobiotic metabolising enzymes are probably involved in the development of colonic carcinoma.

5.   Twenty eight colonic carcinoma tumours were examined, all of which were moderately differentiated adenocarcinomas.