Hi, my name is Marsha, and I have had my ileostomy for more than 50 years, since I was 15.
Surgery was a last resort after a 2 1/2 year battle with UC, frequent bloody losses - 20 times a day, treatments with medications that caused other lasting conditions (osteoporosis), 50 pounds of water weight gain (steroids), and almost a year in the hospital over that 2 1/2 year time period. Like you, after the first two surgeries my large intestine was removed, but I was left with the rectal stump, which never healed. When I was 18, I fought with my doctors and my parents to have the final surgery and remove the stump. The doctor argued that "someday" they would be able to reconnect people who have had that surgery. At the time, I was adamant that I never wanted to take the chance of having a recurrence of the disease. And so a year later, I had my final surgery (I was 19) and I have had no regrets. Through the years, there have been advances in procedures that allow for reconnection. A "hook up", ileum to rectal stump, results in frequent trips to the bathroom, especially after eating. I had friends who had that surgery, and they weren't happy with the results. The most successful are those that involve creating a "pouch", but that doesn't always work well, and there are often leaks... or needed revisions...
So, back to your original question, can a reversal be done? Or more to the point....do you want to take the risk that all will be well? If you really have/had Ulcerative Colitis, then I would think it would be risky, since the rectal area is still vulnerable. If you didn't really have UC, then there would probably be a better chance of success.
Both my grown sons have inflammatory bowel disease...one has Crohn's, and the other has UC. Both have been on medications for years, but my younger son is now on an anti-inflammatory, organic, vegan diet (along with his wife and 2 young sons). He is now off all medication for the first time in 20 years.
You have a difficult decision to make, so do your research well, and do what is best for you.
I wish you the best of luck.