CLINICAL anatomy.
D001003:Anal Canal / Q000033:anatomy & histology*; D003106:Colon / Q000033:anatomy & histology*; D006652:Histological Techniques; D006801:Humans; D012007:Rectum / Q000033:anatomy & histology*
ANUS/anatomy and histology; COLON/anatomy and histology; RECTUM/anatomy and histology