Comparison of the color of fecal blood with the anatomical location of gastrointestinal bleeding lesions: potential misdiagnosis using only flexible sigmoidoscopy for bright red blood per rectum

Abstract

Objective: Flexible sigmoidoscopy has been recommended for diagnosis of patients with bright red rectal bleeding. The purpose of this study was to determine whether lesions associated with bright red hematochezia are located in the distal 60 cm of the colorectum and, therefore, in reach of a flexible sigmoidoscope.

Methods: Three hundred-twelve consecutive patients presenting with hematochezia were shown a card containing three shades of red and asked to choose the color most representative of their fecal blood. Patients then underwent colonoscopy. The colonoscopist noted the length of the scope inserted when bleeding lesions were found.

Results: Of 217 patients with bright red hematochezia, 181 bled from the distal 60 cm of the colon, 20 had more proximal lesions (including eight with cancer), and 16 had no lesion found. However, 140 patients with rectosigmoid neoplasms or nonbleeding nonneoplastic lesions (e.g., hemorrhoids, diverticula, vascular anomalies, and fissures) if found by sigmoidoscopy would have subsequently required full colonoscopic surveillance. It was calculated that the average per patient medical charges employing an initial colonoscopic approach would save $12 or $116 over one beginning with sigmoidoscopy (depending on whether sigmoidoscopy is performed in an office setting or endoscopy suite, respectively), and would reduce the probability of perforation slightly.

Conclusion: A diagnostic approach to hematochezia beginning with colonoscopy should be more effective, safer, and less costly than one beginning with flexible sigmoidoscopy, even when the blood is bright red.