Colonoscopy in the diagnosis of unexplained rectal bleeding

Area of Science:

• Gastroenterology
• Colorectal Surgery

Background:

• Obscure rectal bleeding often requires advanced diagnostic methods after initial evaluations.
• Standard proctoscopy and barium enema may not identify the source of bleeding.

Purpose of the Study:

• To determine the diagnostic yield of colonoscopy in patients with obscure rectal bleeding.
• To evaluate the reliability of patient-reported bleeding versus physician-observed bleeding.

Main Methods:

• Colonoscopy was performed on 105 patients with unexplained rectal bleeding.
• Diagnostic yield was compared based on bleeding observation (physician vs. patient).

Main Results:

• Colonoscopy yielded a diagnosis in 17% of cases (18 of 105 patients).
• Lesions identified included carcinomas, polyps, colitis, and proctitis.
• Physician-observed bleeding had a higher diagnostic yield (22.5%) than patient-reported bleeding (5.9%).
• Most lesions (16 of 18) were located in the left colon.

Conclusions:

• Colonoscopy is valuable for diagnosing obscure rectal bleeding when initial workup is inconclusive.
• Physician-observed bleeding is a more reliable indicator for colonoscopy referral.
• Standard workup should include history, physical exam, sigmoidoscopy, and barium enema; colonoscopy is indicated for persistent or observed colonic bleeding.