Sigmoidoscopic and radiological study of the recto-sigmoid junction.

Adequate investigation of the left side of the large bowel and the rectum requires examination by sigmoidoscope and by barium enema. In the lower pelvic colon and the upper rectum these investigations are complementary and sigmoidoscopy may give a clue to disease higher up. Welin (1958) is of the opinion that, using the double contrast method, barium examination of the rectum is in many cases superior to proctoscopy. However, doubt remains whether these investigations overlap and whether the 'sigmoidoscopic' recto-sigmoid junction is the same as the 'radiological' recto-sigmoid junction or whether there is a gap between them. In an attempt to resolve this doubt a method of marking the bowel at sigmoidoscopy was devised so that levels could be indicated to the radiologist. This method is also of value in marking lesions seen at sigmoidoscopy for subsequent radiological investigation. METHOD