The Role of Anorectal Manometry in Diagnosing and Guiding Management of Pediatric Chronic Refractory Constipation

Structural and functional abnormalities of the anorectum or pelvic floor have been observed in constipated children with or without fecal incontinence. Childhood functional constipation accounts for about 95% of cases, while organic causes are less than 5%.

Organic causes include Hirschsprung disease, anorectal malformations, neuromuscular disorders and metabolic causes. Functional constipation can be caused by paradoxical contraction or insufficient relaxation of the pelvic floor muscles, and/or inadequate rectal propulsive forces during defecation. According to the Rome IV criteria, functional constipation is defined separately for infants and toddlers (<4 years) and for children (≥ 4 years).

Anorectal manometry (ARM) is an objective tool used to measure pressure and sensation in the anorectum at rest, during squeezing, and during simulated evacuation. three dimensional high resolution anorectal manometry (3D-HRAM) employs an array of 256 sensors, offering a more detailed assessment of anorectal anatomy and function.

Anorectal manometry is used for the evaluation of chronic constipation by checking rectoanal coordination and rectal sensitivity, and helps exclude structural disorders. It evaluates fecal incontinence by analyzing sphincter function and rectal sensation, identifies sphincter hypertension in functional anorectal pain, and provides preoperative baseline data before surgeries affecting continence or defecation.

Treatment of childhood constipation includes both nonpharmacological approaches (education, dietary modifications, behavioral strategies, biofeedback, and pelvic floor physiotherapy) and pharmacological options (osmotic and stimulant laxatives, probiotics as well as newer medications such as prucalopride and lubiprostone). For children with persistent constipation transanal irrigation, botulinum toxin injections, neuromodulation, and surgical procedures may be considered.