Variables in the preparation of the large intestine for double contrast barium enema examination.

This study examines which methods are most appropriate for preparation of the large bowel for double contrast barium enema. Two proprietary laxatives, X-Prep and Picolax, mechanical colonic lavage, and dietary restriction were evaluated in a randomised study of 160 patients. Four alternative preparations were compared with or without dietary restriction. The four preparations were X-Prep alone, X-Prep plus lavage, Picolax alone, and Picolax plus lavage. Scoring of the radiographs was carried out on a double blind basis. Picolax proved superior to X-Prep overall (p less than 0.01) but this was almost entirely because of its greater effect in the right colon and transverse colon. Cleansing in the left colon and rectosigmoid was similar with both laxatives. Restriction of solid food improved bowel cleansing and gave better results than mechanical lavage. The addition of a colonic lavage in starved patients did not significantly improve the quality of bowel preparation with either laxative.