Fibreendoscopy of the intestines.
D003108:Colonic Diseases / Q000175:diagnosis; D019723:Endoscopes; D004724:Endoscopy; D005336:Fiber Optic Technology; D006471:Gastrointestinal Hemorrhage / Q000209:etiology; D006801:Humans; D007410:Intestinal Diseases / Q000175:diagnosis*; D009780:Occult Blood; D013272:Stomach Diseases / Q000175:diagnosis; D013276:Stomach Ulcer / Q000175:diagnosis