Delayed retrograde jejunogastric intussusception after Roux-en-Y gastrojejunostomy: an uncommon complication in an unexpected anatomy

We report the case of a man in his 60s presenting with 2 days of persistent bilious vomiting, with mild abdominal tenderness. His history was significant for a gastric surgery 40 years earlier, although no operative records or indications were available. There was no history of obesity, malignancy or weight change before or after the index procedure. CT and upper gastrointestinal endoscopy findings were suggestive of retrograde gastroenteric intussusception. Given the concern for bowel ischaemia due to the duration of complaints, an exploratory laparotomy was performed, with intraoperative confirmation of a Roux-en-Y gastrojejunostomy (RYGJ). Following adhesiolysis, the intussusceptum-an unusually long, retrocolic Roux limb (approximately 80 cm) anastomosed to an unresected stomach-was reduced and fixed to the mesocolon to avoid recurrence. Postoperative recovery was uneventful, and monthly follow-up showed no recurrence of symptoms or complications. This is, to our knowledge, the first reported case of retrograde jejunogastric intussusception following a non-bariatric RYGJ.