One-anastomosis gastric bypass- Minigastric bypass (OAGB-MGB) is an emerging bariatric surgery technique replacing the RYGP with reasonable short- and long-term side effects. Here we would like to present a late complication of OAGB-MGB associated with signs of peritoneal irritation and severe pain due to transient midgut volvulus associated with chylous ascites.. We observed peritoneal lymphatic collection in association with features suggestive for small bowel obstruction 3 years followingOAGB-MGB. So, we believe that such complication should be considered as a potential side effect during short and long term follow up after gastric bypass.A strong recommendation should be provided.