Factors predisposing to radiation-related small-bowel damage.

From 1970 through 1977, 92 patients with ovarian cancer received 20 Gy (2,000 rad) to the abdomen, followed by 30 Gy (3,000 rad) to the pelvis. Small-bowel obstruction developed in 7 (7.6%). The number of previous laparotomies, thin physique, and hypertension were significantly associated with complications. Two patients receiving isoniazid and 2 receiving Premarin had enteric complications. Pre-existing vascular damage may potentiate radiation damage to the small bowel.