A critical consideration of diseases of the large colon supports our belief that whenever a barium enema or sigmoidoscopy is indicated for diagnosis, the other is equally desirable. Both procedures have overlapping and supplementary spheres of applicability.
The direct visualization and easy access afforded by the use of the sigmoidoscope is of definitive value. Beyond the view offered by the use of the sigmoidoscope, barium studies with fluoroscopy and roentgenography are necessary. Barium studies of the rectum contribute little to diagnosis.1 Inflammatory and ulcerative disease of the large colon may, in the early stages, be confined to the rectum. In idiopathic ulcerative colitis, the rectum and lower sigmoid colon are involved in 95% of the cases of this disease. A large percentage, 60 to 75%, of colonic tumors occur in areas of the lower bowel accessible to the sigmoidoscope.2 Spastic phenomena and functional colitis involving the sigmoid and