In this technique, a small, soft balloon is inserted into the rectum and is attached to a large syringe that will inject either water or air into the balloon, causing the balloon to enlarge within the rectum.

(Image Credit: CMT Medical)

This training technique allows the patient to provide feedback about sensation of rectal filling including when the patient perceives urges to defecate. The patient can practice expelling the balloon, and in the event of a dyssynergic pattern of pelvic floor muscles, the balloon would not be expelled due to increased muscle tension and shortening of the anorectal area. In this manner, the patient is trained to bring awareness to the anorectal area, and to respond with healthy patterns of defecation.

(Reference: Holly Tanner, Herman and Wallace. Check out the link for details and more information)