Significance of distal polyps detected with flexible sigmoidoscopy in asymptomatic patients

Colorectal cancer is a frequent cause of death from cancer. To reduce the mortality associated with this disease, regular flexible sigmoidoscopy is recommended. However, the significance of diminutive polyps (adenomatous or hyperplastic) detected during flexible sigmoidoscopy remains controversial, as does the appropriate endoscope length (35 vs 60 cm) for colorectal cancer screening.

One hundred one consecutive patients with no history of colonic disease, gastrointestinal tract symptoms, or positive results of fecal occult blood testing underwent flexible sigmoidoscopy as part of a colorectal cancer screening program. All patients with distal polyps detected during flexible sigmoidoscopy underwent colonoscopy.

More than 25% of these asymptomatic, predominantly male subjects had colonic neoplasms or polyps detected. Fifty percent more lesions could be detected with a 60-cm sigmoidoscope than with a 35-cm sigmoidoscope, and detection of any distal polyp, whether adenomatous or hyperplastic, was associated with at least one proximal colon adenoma in 20% of patients. "Extended flexible sigmoidoscopy" for colorectal cancer screening was well tolerated by patients, as evidenced by insertion to the hepatic flexure in 25% of patients, and provided significantly more information than could be obtained with a 35-cm sigmoidoscope.

Colorectal cancer screening should be performed with a 60-cm flexible sigmoidoscope, and distal colonic polyps or neoplasms will be detected in 25% of asymptomatic patients.