title: Toxic megacolon after proctosigmoidoscopy in ulcerative colitis.
mesh_terms: D003093:Colitis, Ulcerative / Q000175:diagnosis* / Q000209:etiology*; D006801:Humans; D008297:Male; D008532:Megacolon, Toxic / Q000209:etiology*; D008875:Middle Aged; D012812:Sigmoidoscopy / Q000009:adverse effects*