OP, I was one of those who was misdiagnosed as well and came here to express my outrage (was told I had UC but now they say Crohns). Some posters, like Scott F, said essentially, "aren't you glad your surgeon didn't mess up the J-Pouch procedure because that would have been mal-practice." So apparently, misdiagnosis is totally in bounds. Apparently, Scott is a doctor and he seems way too sympathetic to other doctors.
To me, it would be no different than performing a double-mastectomy on someone who didn't have breast cancer but rather a harmless lump and then saying "yeah but hey, look what a great job I did with your surgery, you're not dead or anything."
Fact is, my surgeon gets paid for cutting. If he had told me I had Crohns and not UC he would have never seen me again and he wouldn't have received the S-ton of money he got from my insurance company.