Abstract
INTRODUCTION: Retrograde colonic intussusception is a rare condition in adults, often caused by organic lesions such as tumors. Autonomic dysfunction in disorders like multiple system atrophy (MSA) might contribute to its occurrence. CASE PRESENTATION: An 81-year-old bedridden woman with a history of MSA presented with severe abdominal pain and abdominal distension lasting 4 days. She had chronic severe constipation managed with laxatives and manual disimpaction. CT imaging revealed retrograde intussusception of the rectum into the sigmoid colon. Endoscopic reduction was attempted but was unsuccessful due to scope impassability. Emergency laparotomy identified a 4-5 cm tumor at the lead point, and manual reduction resulted in bowel perforation. Hartmann's procedure with D2 lymphadenectomy was performed. The tumor was histopathologically diagnosed as a tubulovillous adenoma with no malignant features. The patient's postoperative recovery was uneventful except for a urinary tract infection (Clavien-Dindo Grade II), and she was transferred to a rehabilitation facility on postoperative day 24. CONCLUSION: Failure of reduction by air enema should raise suspicion for retrograde intussusception, warranting prompt surgery if an organic lead point is suspected.