In select patients with gunshot wounds, no operation is sometimes a better option
At one time, trauma surgeons considered an operation mandatory to treat gunshot wounds to the abdomen, but a study has found that in selected patients, avoiding an operation -- a practice known as nonoperative management -- is an acceptable and effective treatment. Ref. Source 3w.
Yeah, I have friends that still have shrapnel inside of themselves. I don't have any with a bullet left inside though. For some it's just too dangerous to dig out all the shrapnel so they left it in. I guess I was lucky or skillful (Mostly lucky) enough to have evaded the lead and explosions meant for me.