I would still consider surgery the treatment of choice unless there were some absolutely unsurmountable contraindication.

I think this would place the patient at unacceptable risk. Toxic megacolon is currently to be regarded as a surgical emergency. A subtotal colectomy should be performed with a long rectal stump sutured closed and sutured to the fascia of the wound. If the stump blows then a mucous fistula will form. The rectum should only be touched if it contains a cancer, is perforated or is bleeding uncontrollably. As a pouch surgeon a short rectal stump is extremely annoying and also unnecessary.