Tissue sampling and analysis.
D001706:Biopsy / Q000592:standards*; D003106:Colon / Q000473:pathology; D016099:Endoscopy, Gastrointestinal / Q000592:standards*; D004947:Esophagus / Q000473:pathology; D005767:Gastrointestinal Diseases / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D007421:Intestine, Small / Q000473:pathology; D012955:Societies, Medical; D013270:Stomach / Q000473:pathology; D014481:United States