Alexander P. Abadir, MD, Christopher Rombaoa, MD, Sunhee Park, MD
University of California Irvine, Orange, CA
Introduction: Acquired megacolon is a rarely diagnosed condition that may be a source of significant distress in the acutely hospitalized patient. It presents in either gender at any age. Symptoms, when present, are typically abdominal pain with distention, gas distress, and constipation. Reported cases are typically less than 10cm on diagnostic imaging. Pathology findings vary greatly and include muscularis hypertrophy or degeneration of the smooth muscle, damaged or reduced ganglia, melanosis coli, or chronic inflammation.
Case Description/Methods: A 19-year-old Hispanic US-born man presented to the ER with severe, progressively worsening abdominal pain and distention for one month and inability to urinate. His last bowel movement (BM) was 3 weeks ago, small and liquid. He stated it was common for him to not have a BM for up to a month. This has occurred since he was six years old, when he began avoiding defecation due to pain he experienced when moving his bowels. Prior treatment with laxatives and enemas had been ineffective in inducing regular bowel movements. He has had difficulty gaining weight.
Initial labs were significant for severe iron deficiency anemia with MCV 65, Ferritin 2, TIBC 301, Iron 11, and percent saturation of 4%. CT imaging showed a markedly distended colon and rectum measuring up to 17cm in the sigmoid colon. There was severe stool burden in the rectum and the distended colon. The colon was causing mass effect and crowding of other organs, including a distended bladder. Initial inpatient management with enemas, disimpaction, and frequent laxatives failed to cause significant reduction in the colonic distention. Under anesthesia, rectal examination found normal rectal tone and required disimpaction and lavage. Full-thickness rectal biopsies were obtained which revealed mild erosion, indeterminate colitis, and hyperplasia of the muscularis mucosa. Calretinin was positive for nerve fibers, however no ganglia were seen. A diverting Brooke ileostomy was created without immediate complications. On 1 month follow up the patient reported significant weight gain, no further abdominal pain, and adequate ostomy output.
Discussion: This case demonstrates a severe example of acquired megacolon in a young man due to chronic constipation. Surgery is typically required for very distended cases, but surgical options vary considerably and have been poorly studied. In this patient, due to the extreme nature of his megacolon, surgical diversion was performed to allow eventual resection.
Citation: Alexander P. Abadir, MD, Christopher Rombaoa, MD, Sunhee Park, MD. P1104 - CHRONIC CONSTIPATION WITH MASSIVE ACQUIRED MEGACOLON IN A 19-YEAR-OLD MAN. Program No. P1104. ACG 2019 Annual Scientific Meeting Abstracts. San Antonio, Texas: American College of Gastroenterology.