The etiology and clinical characteristics of acute lower gastrointestinal bleeding in patients hospitalized for comorbid illnesses.

BACKGROUND/AIMS: To determine whether there are different causes of acute lower gastrointestinal bleeding and different clinical courses in patients (a) with comorbid illnesses vs. (b) patients with only severe hematochezia.
METHODOLOGY: From January 2001 to December 2003, 107 hospitalized patients with acute lower gastrointestinal bleeding were evaluated by urgent colonoscopy. Our analyses compared the etiology and clinical characteristics of bleeding in patients with (group A) and without (group B) one or more comorbid illnesses.
RESULTS: Group A patients tended to have longer hospital stays, more severe anemic conditions, and more transfusion requirements. The overall mortality rate was 29.5% in group A and 4.3% in group B (p < 0.05). Bleeding-related mortality was not significantly different between groups. Colitis, rectal ulcer, and angiodysplasia were the leading causes of lower gastrointestinal bleeding in group A. Rectal ulcer was a more common cause of bleeding in group A (16.4%) than in group B (2.1%) (p < 0.05), and it resulted in longer hospital stays and more severe anemia and leukocytosis compared to patients with other causes of lower gastrointestinal bleeding.
CONCLUSIONS: Patients with acute lower gastrointestinal bleeding that starts after hospitalization for other comorbid illnesses have distinctive etiologies and clinical characteristics compared with ordinary patients admitted to the hospital with only bleeding. Rectal ulcer is an important but obscure cause of acute lower gastrointestinal bleeding in elderly patients with significant comorbid diseases.