English: Gross pathology of a longitudinally opened colon after formalin fixation, showing normal mucosa (left) and mucosa with severe ulcerative colitis (right), forming pseudopolyps (smaller than the cobblestoning typically seen in Crohn's disease), over a continuous area (rather than skip lesions of Crohn's disease), and with a relatively gradual transition from normal colon (while Crohn's is typically more abrupt).