Episodes of exacerbation and remission are commonly encountered in inflammatory bowel disease. 
Some of the long term commonly encountered complications include bowel strictures, adhesions, enterocutaneous or enteroenteric fistulations, intra abdominal abscess formation.

The prior study of this patient done 5 months ago (images not provided) did show the extensive large bowel involvement, however no fistulation existed. This is a new development. No intra-abdominal abscesses are present though.