It does not mean that the pouch itself failed because of the cuffitis.
Pouch failure generally means either defunctioning the pouch with a diverting stoma or pouch removal with ileostomy. So, in regard to the cuffitis, failure means intolerable symptoms that do not repsond to treatment, or intolerable side effects of the treatment. The end result is the same of no functioning j-pouch.
Jan