Historically, acute lower intestinal bleeding has incorporated small bowel with colonic sources. This potentially obscures the unique characteristics of small bowel bleeding, which are eclipsed by the attributes of the much more common colonic bleeding. Separating acute lower intestinal bleeding into small bowel and colonic sources may delineate characteristics of each, thereby making it possible to determine whether clinical outcomes vary by anatomic level of bleeding.

A total of 29 consecutive patients (15 women, 14 men; age 68.6 ±2.4 years) with acute small bowel bleeding were compared with two other groups, each with 29 consecutive patients, with either acute colonic bleeding or acute upper GI bleeding. Clinical presentation, outcomes, and resource utilization for small bowel bleeding were compared with similar parameters for acute colonic bleeding and upper GI bleeding.

Although the clinical presentation did not always distinguish the 3 groups, resource utilization was significantly higher in the small bowel bleeding group. The latter group required a higher number of diagnostic procedures (p < 0.001) and blood transfusions (p < 0.001), remained in hospital longer (p < 0.05), and had a higher cost of hospitalization (p < 0.001) compared with the colonic bleeding and upper GI bleeding groups. The mortality rate for patients with small bowel bleeding was 10%. Although none of the patients with upper GI bleeding and only 14% of those with colonic bleeding required greater than 3 diagnostic procedures, 79% of patients with small bowel bleeding required 4 procedures for diagnostic localization (p < 0.0001).

Small bowel bleeding (“mid-intestinal bleeding”) is a distinct clinical entity with significantly worse outcomes compared with colonic bleeding and upper GI bleeding. The focus of the investigation should be directed to the small bowel, with enteroscopy or capsule endoscopy, when 3 investigative procedures fail to localize recurrent overt GI bleeding.