There is a part where the doctors are doing surgery and you see bloody scalpels, lots of blood on their hands, and blood on their masks. Could be disturbing to some, but only lasts about fifteen seconds.
Hunter gets a liver transplant and it is a very disturbing seen, insides are shown along with the actual liver transplant
All of the surgery scenes are very disturbing and realistic with a lot of blood, and not for people with weak stomachs.