I'd advise not to eat too much, so you don't crap too much.
Your prob going to be constipated from the anesthesia/pain meds, so remember not to "push".
Also, something you wouldn't immediately think about, be careful getting out of bed. Naturally we rely on a lot of core strength to do so and thats really what you want to avoid. If you happen to have any heavy furniture near your bed, tie a bed sheet to it and the upper corner of your bedframe if you have one. When you go to get out of bed, simply untie it and use your arm strength to hoist yourself in an upright position.
That advice helped me a lot.
Good luck and get rest.