Hey Lyndsey,
I am 51 years old, and was very active and healthy prior to my rupture. I too just had a reversal due to perforated diverticulitis, with peritonitis. My rupture was in March of 2016 and the reversal was in Nov 2016. I came through the resection surgery and felt fantastic! Way better than the first time. A couple of days in, my body decided it was not having anything to do with this and I got an ileus for the next 12 days. That was not fun. I was determined that I was not getting that bag back and started doing some yoga moves while lying in bed. (knees up towards the side of your chest, called the wind removing pose) I needed help from my family to get my knees up there, LOL, but by the end of the day, things started moving. Ya Hoo! All went well after that and I was out of the hospital 3 days after the first movement. If it wasn't for the ileus, all would have been great. One thing you should do is make sure you walk afterwards, I did a walk around the hospital halls every hour. Even with the ileus, I still tried to walk once an hour. Some walks were longer than others, but as long as you walk a bit, things will heal quicker. I am now 3 months past surgery and I have a partial blockage at the reconnection site. I will be going in on Monday to get it stretched out. It is rare, and is done through a colonoscopy, so no big deal. It has been a rough go, but in the end, it is worth it all. You are young, you will bounce back quickly.
I too read all the stories posted here and was quite horrified to go through with the surgery, but then I kept thinking people don't post the good stuff, just the bad stuff. Take all the bad stories with a grain of salt, and keep thinking positive! Don't worry, it is a very routine procedure nowadays. You have already gone through the rough stuff. You got this!
Good luck!