Conditions which can make the diagnosis of ulcerative colitis challenging:
(1) presence of a superimposed colitis
(2) inadequate or misleading information
(3) fulminant disease
Conditions where some findings may be lacking:
(1) following therapy
(2) low grade disease in remission
(3) initial presentation in a pediatric patient
Situations which may cause confusion with Crohn’s disease:
(1) presence of backwash ileitis
(2) appendiceal involvement
(3) false impression of skip lesion when there is cecal and/or ascending colon involvement
(4) involvement of the duodenum or other upper gastrointestinal site
(5) relative sparing of rectum
(6) granuloma associated with rupture of a crypt abscess
(7) presence of a superficial fissure
