11.biopsy sample (H&E stain)that demonstrates marked lymphocytic infiltration (blue/purple)of the intestinal mucoma and architectural distortion of the crypts.the best test for diagnosis of ulcerative colitis remain endoscope.full colonoscopy to the cecum and entry into the terminal ileum is attempted only if diagnosis of UC is unclear.otherwise,a flexible sigmoidoscopy is sufficient to support the diagnosis.the physician may elect to limit the extent of the exam if severe colitis is encountered to minimize the risk of perforation of colon.