My Father Has Colon Cancer, Last Stage. His Liver Also

My Father has colon cancer, last stage. His liver also got affected by this and has got liver cirrhosis and it has damaged his liver by 70%-80%. He is also diabetic.

One of the Doctor in a local hospital suggested an operation to bypass his large Intestine so that the Stool may pass normally and he can have some food. Is it possible for him to survive this Operation or should we let it go. Kindly advise.