Late gastrointestinal disorders after rectal cancer surgery with and without preoperative radiation therapy

Background: The aim of the study was to analyse late gastrointestinal disorders necessitating hospital admission following rectal cancer surgery and to determine their relationship to preoperative radiation therapy. Methods: Curatively treated patients participating in the Swedish Rectal Cancer Trial during 1987-1990, randomized to preoperative irradiation (454 patients) or surgery alone (454), were matched against the Swedish Hospital Discharge Registry. Hospital records for patients admitted with gastrointestinal diagnoses were reviewed. Results: Irradiated patients had an increased relative risk (RR) of late small bowel obstruction (RR 2.49 (95 per cent confidence interval (c.i.) 1.48 to 4.19)) and abdominal pain (RR 2.09 (95 per cent c.i. 1.03 to 4.24)) compared with patients treated by surgery alone. The risk of late small bowel obstruction requiring surgery was greatly increased (RR 7.42 (95 per cent c.i. 2.23 to 24.66)). Irradiated patients with postoperative anastomotic leakage were at increased risk for late small bowel obstruction (RR 2.99 (95 per cent c.i. 1.07 to 8.31)). The risk of small bowel obstruction was also related to the radiation technique and energy used. Conclusion: Small bowel obstruction is more common in patients with rectal cancer treated with preoperative radiation therapy.