The investigation of colorectal disorders.

The investigation of colorectal disorders follows from a thorough clinical examination, examination of stools, and proctosigmoidoscopy. In many patients, barium enema examination will also be required, and the value of good air contrast examinations is stressed. Colonoscopy has revolutionised the diagnostic and therapeutic capabilities in colonic disease, but this examination is not readily available to all, its indications limited, and the risks and discomfort associated with it by no means small. In New Zealand, colorectal cancer is as common as anywhere else in the world, and the major hope of any improvement in this area is with preclinical diagnosis. This could be achieved by more widespread faecal occult blood testing especially in high risk groups (Table 2) and thorough investigation of those with positive results. Serological tests for colorectal cancer (carcino-embryonic antigen) have proved disappointing, and much less specific than originally hoped.