First - make sure you trust your doctor with your life. This is a very intricate operation and the wrong doctor can make the whole experience horrible - as it was in my case. I had 23 hemorrhoids removed 8 years ago. I had those same hemorrhoids for about 30 years, I got them when I was 18 and pregnant. They just never went away or got smaller. I finally had problems with them seeping blood because the skin was so thin. I HAD to have the surgery.
The biggest problem I had was getting enough fiber to make the bowel movements large enough to stretch my anus to the proper size. I still have problems with that because my doctor just said to eat better, but gave me no idea of what to eat. You want to make sure you eat lots of insoluable fiber. You know that kind that just doesn't digest - like shredded wheat. Ask your doctor for a list of high fiber foods you should eat post surgery. Also it is necessary to take a good stool softener. Your pain level will be high at first and thank God for good pain meds that don't constipate. I had trouble getting around because let's face it your butt is in the middle of your legs, so the discomfort (after pain meds and then after some healing) effects all of your life. I healed very slowly due to the problem I had with small sized bowel movements.
I think my doctor was a quack and when I went for my regular exam at my gyn, she thought so too. She offered to testify when I sued him for messing up my surgery. I didn't sue. Within a year I had 13 new hemorrhoids. Not normal I'm told by others who had the surgery.
Be SURE you trust your doctor. If you have any doubts about his/her ability to make this experience as painless and successful as possible, put off the surgery until you find a colo-rectal doctor you trust.
Others that I have spoken to had very short recovery time and had no problems with bowel size because their doctors advised them appropriately on what type of food to eat as well as which stool softeners to use. Try very hard to get those stools large because even though they are a little uncomfortable (not very because of the stool softener) it is worth it to get your anus appropriately large.
Expect to have considerable pain within the first few hours of the surgery. My doctor gave me Demoral which is not a very effective pain reliever and didn't relieve pain in my case. I had to wait 4 hours for the next pain med, which thankfully worked. Discuss with your doctor what he plans to give you for pain immediately after the surgery. You should wake up with discomfort, not pain. If you have had any surgery before, you should have an idea of which pain med works well for you.
Good luck! I hope I haven't been too much of a nay-sayer. Like I said, others I talked to had none of the problems I had. They, however, trusted their doctor and talked over all the areas that I had problems with before the surgery.