Bowel preparation before sigmoidoscopy
Sir
We agree with Mann et al. (Br J Sury 1988; 75: 425-7) that preparation of the distal bowel, by means of disposable phosphate enema, is helpful before rigid sigmoidoscopy. However, when the facilities are available in the out-patient department to give enemas to patients requiring sigmoidoscopy the opportunity should be taken to examine the patient with a flexible, fibreoptic instrument whenever possible. A disposable enema will adequately prepare the bowel as far proximally as the splenic flexure in most cases and full insertion of a 65 cm flexible endoscope can be achieved in over 70 per cent' of cases. Examination of at least 30 cm of bowel (the maximum distance achievable with a rigid instrument) is possible in almost all patients. In fact, Mann et al. achieved passage of the rigid sigmoidoscope a mean distance of only 22.4 cm, despite bowel preparation and placing the patient in the unpopular knee-elbow position. Allowing for the apparent distance passed due to stretching of the rectum, this suggests that the rectosigmoid junction remains a difficult obstacle to negotiate with the rigid instrument.
However, the greatest argument for use of the flexible sigmoidoscope is that it will increase the number of occasions where cancer is diagnosed at a patient's first hospital attendance, simply owing to the extra length of bowel examined. In our experience, diagnosis of cancer at the initial consultation, without need for further investigation such as barium enema or colonoscopy, significantly reduces the delay between a general practitioner referring the patient and surgery. We suggest that any surgeon with the opportunity to give patients limited bowel preparation in the out-patient department would d o better to invest in a flexible sigmoidoscope than a Ritter table.