Metastatic colorectal cancer to the small bowel-an uncommon cause of obscure GI bleeding: a three-case experience with review of the literature.

PURPOSE: Metastatic colorectal cancer to the small intestine is a rare condition presenting with nonspecific symptoms such as obscure gastrointestinal bleeding (OGIB). We report our experience with the use of capsule endoscopy (CE) and double-balloon enteroscopy (DBE) to identify and diagnose the metastatic colorectal cancer to the small bowel. The aim was to demonstrate the approach to the diagnosis of metastatic colorectal cancer to the small bowel including literature review.
METHODS: This is a retrospective case series from an academic tertiary referral center. Three patients with a history of colorectal cancer referred for OGIB underwent CE and subsequent DBE.
RESULTS: All patients underwent evaluation including esophagogastroduodenoscopy and colonoscopy prior to referral. In each case, CE was performed revealing the source of bleeding which was confirmed as metastatic colorectal cancer to the small bowel by DBE. Significant lag time was noted from the initial diagnosis of colorectal cancer to the onset of symptomatic small bowel metastasis in this series (1.3-7 years).
CONCLUSIONS: We found the incidence of metastatic colorectal cancer to the small intestine of those with small intestine tumors to be 6%. Clinicians should be suspicious of this condition in any patient with OGIB and prior history of colorectal cancer. The approach to this diagnosis is varied but one algorithm includes the combined use of CE for tumor localization and balloon-assisted enteroscopy for confirmation.