The IRA procedure is done rather commonly for people with Crohns where the disease does not involve rectal area. There is always the possibility that Crohns may show up in the rectum but more often than not it doesn't. So these can be very successful in Crohns.
I have never heard of it being done for people with UC, though as with most things it likely has been done. I looked into a partial removal of the colon as I had limited disease and it was well controlled, this after I was diagnosed with cancer. I had, had UC for 25 years and I found there is very little documented info and no studies as to success that I came across. Partial removal of the colon in UC, except in emergencies, just isn't done very often.