Anorectal manometry is a technique used to measure contractility in the anus and rectum. This technique uses a balloon in the rectum to distend the rectum and a pressure sensor at the internal anal sphincter to measure the presence or absence of the rectosphincteric reflex. Anorectal manometry is a technique used to measure contractility in the anus and rectum. This technique uses a balloon in the rectum to distend the rectum and a pressure sensor at the internal anal sphincter to measure the presence or absence of the rectosphincteric reflex. It may be used to assist in the diagnosis of Hirschsprung disease in which there is an absence of the rectosphincteric reflex that should relax the internal anal sphincter upon distension of the rectum. It is also used in the assessment of rectocele.