What is the likelihood of death and complications of gastric bypass?

Gastric bypass risk: It depends on where you have surgery. Nationwide, the risk of death is about 1/500 to 1/1000 operations. However, if you go to a highly specialized center with a long track record, the risk can be much less than that. A bypass is a fairly difficult operation, whereas a lap band is very easy. I would only trust my associate and a handful of colleagues to do a bypass on myself or a relative.