Primary colonoscopy.

There is good evidence that colonoscopy, in expert hands, is the most accurate investigation for the diagnosis of colorectal disease, and it also allows histological confirmation and therapeutic procedures to be carried out. Furthermore, by screening high-risk groups together with regular follow-up of patients with known colorectal neoplasia and surveillance of long-standing ulcerative colitis patients, it may be possible to reduce the incidence of colorectal cancer. However, at the present time, the lack of widespread availability and the variability in the quality of examinations precludes the employment of colonoscopy as the first-line investigation in colorectal disease. Flexible sigmoidoscopy combined with good quality double contrast barium enema is a reasonable alternative in the majority of cases, reserving colonoscopy for investigation of the elderly and high-risk patients, together with surveillance of patients with premalignant conditions. Technologically, colonoscopy has probably reached its peak and it is now necessary to make provision for more widely available colonoscopy services, provided by adequately trained endoscopists who can guarantee total colonoscopy in more than 90% of cases safely and rapidly. This requires structured training programmes for gastrointestinal physicians and surgeons and ultimately changes in patterns of working practice if adequate numbers of colonoscopy sessions capable of dealing with a steadily increasing workload are to be achieved.