@ DM, I had a large op about 12 years ago fer diverticulitis to removed some infected colon. 38 metal staples holding my tummy together after, and 2 days in intensive care.
So a few tips fer you;
Don't go mad on the morphine after the op, they will give you your own drip button to press when you need a hit fer pain relief, the morphine is great and it does the job but morphine is really only heroin under a different name but made in proper labs. Morphine is a opioid as in it comes from the opium poppy just the same as heroin. Like I said it does a good job but the come-down after can be pretty daunting to put it mildly.
Secondly you might be going to be 'Kleen-preped' the day before the op, that is to drink about 8 pints of Kleen prep mixed in water to flush out your whole system before the op, if'n they are going to do that to you, let me know and I will give you some toilet advice on that.