Structure and function of the internal anal sphincter.
D001003:Anal Canal / Q000002:abnormalities / Q000033:anatomy & histology / Q000502:physiology / Q000503:physiopathology; D002648:Child; D003248:Constipation / Q000151:congenital; D004576:Electromyography; D019723:Endoscopes; D004848:Epithelium; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008531:Megacolon / Q000503:physiopathology; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000502:physiology; D012867:Skin