Here is another example of extensive ulcerative colitis (UC). The ileocecal valve is seen at the lower left. Just above this valve in the cecum is the beginning of the mucosal inflammation with erythema and granularity. As the disease progresses, the mucosal erosions coalesce to linear ulcers that undermine remaining mucosa. Colonoscopic views of less severe UC are seen below, with friable, erythematous mucosa with reduced haustral folds.