S4496 Bowel Patrol: When Methadone Maintenance Meets Megarectum

Introduction: Stercoral colitis, though uncommon, is a potentially life-threatening complication of opioid-induced constipation (OIC). Methadone, a long-acting μ-opioid receptor agonist, is known to markedly slow gastrointestinal transit. Sustained fecal retention may lead to colonic wall ischemia, necrosis, and perforation. Early recognition is critical to preventing fatal outcomes, especially in patients undergoing opioid maintenance therapy. Case Description: A 53-year-old man on methadone maintenance therapy of 140 mg daily presented with 1 month history of worsening abdominal distension, pain, and intractable constipation. He had not passed stool in over 3 weeks despite using over-the-counter laxatives and stool softeners. On examination, the abdomen was distended and tympanic with hypoactive bowel sounds. Laboratory data revealed leukocytosis (white blood cell 14.8 × 10⁹/L) and elevated C-reactive protein (92 mg/L). Non-contrast computed tomography of the abdomen and pelvis showed severe fecal impaction in the rectosigmoid colon, colonic dilation consistent with megarectum measuring about 9 cm, mural thickening, and pericolonic fat stranding—findings indicative of stercoral colitis. Conservative treatment including enemas, osmotic and stimulant laxatives, and manual disimpaction failed. Given increasing discomfort and risk for perforation, the patient underwent surgical disimpaction under general anesthesia. Intraoperatively, a 6 lb stool mass was removed. The colon was edematous but intact. Postoperative recovery was uneventful with restoration of normal bowel function on a comprehensive bowel regimen. Discussion: Chronic opioid use, particularly methadone maintenance therapy, can lead to serious complications such as stercoral colitis and megarectum due to impaired gastrointestinal motility. While most cases of opioid-induced constipation respond to conservative treatment, this case highlights the critical need for early recognition and escalation when high-risk features emerge. Surgical referral is warranted when medical management fails or imaging reveals signs of impending complications. In this patient, prompt surgical intervention prevented perforation and led to full recovery. Preventive strategies—including structured bowel regimens, use of peripherally acting μ-opioid receptor antagonists, and standardized OIC screening—are essential to mitigate morbidity in long-term opioid users.