Management of Hematochezia with Inconclusive Colonoscopy and Bleeding Around Ileocecal Valve

Diagnostic Algorithm for Obscure Lower GI Bleeding

Repeat colonoscopy is recommended as the first step when initial colonoscopy is inconclusive but suggests bleeding around the ileocecal valve 1, 2
A thorough bowel preparation is essential to improve visualization, as poor preparation may have led to incomplete evaluation of the colonic mucosa in the first examination 1
The diagnostic accuracy of colonoscopy ranges from 72-86% in patients with lower gastrointestinal bleeding 1

If repeat colonoscopy fails to identify the source, radionuclide imaging with [99Tcm] pertechnetate-labeled red blood cells should be considered 3, 4
Scintigraphy can detect active bleeding at rates of 0.1-0.5 mL/min and is more sensitive than angiography 3
Early scans (<4 hours after baseline) are more helpful in localizing the bleeding site than delayed scans 3
Angiography should be performed only after positive scintigraphy or in patients with hemodynamic instability and severe unremitting bleeding 3, 4
Angiography requires a bleeding rate of at least 1 mL/min for accurate detection of extravasation 3
A positive red blood cell scan should necessitate urgent angiography within 1 hour of positive scintigraphy 3

Angiodysplasia is a common cause of obscure GI bleeding, accounting for up to 80% of cases 5
Small bowel tumors are the most common cause of obscure bleeding in patients younger than 50 years 5
Colonic angiodysplasia are most common in the cecum and proximal ascending colon (54%), followed by the sigmoid colon (18%) and rectum (14%) 1

Assess bleeding risk prior to the procedure with correction of coagulopathy if present, as recommended by the American Society for Gastrointestinal Endoscopy 6

Inadequate bowel preparation leading to poor visualization of the mucosa 1
Use of narcotic medication for sedation may decrease the sensitivity of colonoscopy for detecting angiodysplasia by transiently decreasing mucosal blood flow 1
Premature resort to more invasive procedures before optimizing endoscopic evaluation, as cautioned by the American College of Gastroenterology 1, 2