Look on it as an opportunity to treat yourself to a nice new nightie (better not pyjamas imo, as they can be a bit uncomfy round your tummy) or even a new fleecy bed jacket and slippers if you can stretch to it. Get some nice (but light) food in for when you come home, something you like to eat but that won't give you wind, and someone else to cook it for you. If possible, get your family to spoil you a bit - you won't feel too ill to enjoy it, just a bit under the weather. Have you got someone who can cook for you and fetch cups of mint tea?
Then you just curl up in bed (nightie, comfy knickers and possibly a sanitary pad, depending on what was done) and sleep off the after-effects of the anaesthetic.
Don't drink anything fizzy.
I've had 2 - first, 2 years ago, was only diagnostic, very quick, was kept in overnight and took a few days to recover properly as however minor the procedure is it still involves a GA and that can be quite a knock to your system, depending on how you react. Second was a seven-hour affair when they removed a chunk of bowel among other things and i was kept in for 2 weeks and took some time to recover. Again, worst thing for me was the GA as I always react badly to them and I was under for a long time.
If it's just diagnostic, no post-op pain to deal with apart from gas as people have mentioned. Put a hot water bottle on your shoulder and take 2 ibuprofen.
If it's operative, post-op pain is at least much less than with open surgery. I was very scared when I had my first minor one, but not at all when I had my big one - it's much less scary when you've done one.