Good luck BA.
If it's just LIS, you will wake up in less pain than you have been in. The incision was quite sore for 2 days, but by the end of the second day, I had stopped taking vicoden and moved to ibuprofen. you'll also notice an immediate difference with your poo.
I found it very beneficial to do some bowel prep--only mushy foods 2 days before surgery (i made some chicken soup and also some beans), don't eat after noon the day before surgery (you can drink broth and miso soup), take your usual meds (MOM or whatever) the night before surgery, and be sure you have pooped completely before being put under.
That way there is nothing to get constipated.
After surgery, just have mush again for the first day (again the chicken soup and beans) and after that you should be fine.