Rare but serious complications include:
- Bleeding in the stool, or black stools
- Leaks in new connections made by weight loss surgery; these usually occur within five days of surgery.
- Blood clots in the lungs, called pulmonary emboli, rarely occur, but if they do, they are the most common cause of death after weight loss surgery. Blood clots can be usually prevented with blood thinning medicines and frequent activity.
- Blood clots in the legs, called deep vein thrombosis, or DVT
- Pneumonia