Fecal occult blood testing. Guidelines for follow-up after positive findings.

Fecal occult blood testing should be performed under optimal conditions to minimize false-positive test results. Obvious bleeding from the rectum or other sources during the test period should be investigated and testing should be postponed. When a fecal occult blood test is positive, colonoscopy is recommended as the definitive method of diagnosis and often of treatment. When a complete colonoscopy cannot be performed, sigmoidoscopy with air-contrast barium enema is the next best alternative for direct visualization of the distal bowel and indirect investigation of the proximal colon.