Other abnormal findings on manometry consistent with chronic constipation include an unsatisfactory generation of the propulsive force needed to defecate and a decreased movement of pelvic floor muscles. Anorectal manometry, especially HR-ARM and HD-ARM, has also been used to evaluate constipation due to structural causes such as a rectocele, an enterocele, or an intra-anal intussusception. Hirschsprung's disease In infants and children, anorectal manometry may be used to assist in the diagnosis of Hirschsprung's disease. The absence of the rectoanal inhibitory reflex (RAIR) is almost always pathognomonic for Hirschsprung's disease in this population. Anorectal manometry is not significantly less sensitive and specific when compared to the gold standard method of diagnosis, rectal suction biopsy. In adults, the absence of the RAIR is less likely due to Hirschsprung's disease and may indicate the presence of megarectum. Functional anorectal pain Functional anorectal pain includes disorders such as levator ani syndrome, proctalgia fugax and unspecified functional anorectal syndrome. Although diagnosis of these disorders is largely clinical, anorectal manometry may be used for further diagnostic assessment. For example, the degree of anal sphincter hypertension may be determined which may be useful information when treating functional anorectal pain with biofeedback therapy. Biofeedback The goal of anorectal biofeedback is to help patients improve defecating behaviors by providing patients with visual and verbal feedback. Visual feedback tools, such as anorectal manometry, are often used to aid patients in learning how to modify their behaviors. Patients may work on improving muscle strength, muscle relaxation or sensation during defecation. The effectiveness of anorectal biofeedback as a treatment remains an ongoing source of debate and research. A systemic review article concluded that although better than placebo, there remained limited evidence demonstrating the effectiveness of anorectal biofeedback for chronic idiopathic constipation. In patients with defecatory disorders, including dyssynergic defecation, pelvic floor biofeedback therapy had been shown to be more effective than laxatives. An American-European Neurogastroenterology & Motility task force (ANMS-ESNM) recommended the use of biofeedback in the short and long treatment of constipation with dyssynergic defecation and fecal incontinence. They did not recommend biofeedback treatment for constipation without dyssynergic defecation, nor in children with constipation. Types Types of anorectal manometry include: Non-high resolution (conventional) manometry (non-HRM) High resolution anorectal manometry (HR-ARM) High-definition anorectal manometry (HD-ARM or 3D-ARM) HR-ARM and HD-ARM are newer methods that use multiple closely spaced sensors in the anus and rectum, compared to 3-6 widely spaced sensors used by