The<unk>  <unk>  (also known as the anal sampling mechanism, anal sampling reflex, rectosphincteric reflex, anorectal sampling reflex, or the fart reflex) is a reflex characterized by a transient involuntary relaxation of the internal anal sphincter in response to distention of the rectum. The<unk>  provides the upper anal canal with the ability to discriminate between flatus and fecal material. The ability of the rectum to discriminate between gaseous, liquid and solid contents is essential to the ability to voluntarily control defecation. The<unk>  allows for voluntary flatulation to occur without also eliminating solid waste, irrespective of the presence of fecal material in the anal canal.
Rectoanal inhibitory reflex
Abdominal reflex
Bulbocavernosus reflex
Glabellar reflex
Gastrocolic reflex
Galant reflex
Optokinetic response
Ciliospinal reflex