Ultrasonography in the Assessment of Obstructive Defecation Syndrome

Chronic constipation is a syndrome characterized by symptoms of unsatisfactory defecation associated with infrequent stools and/or difficult stool passage. The pooled prevalence in the community is 14% worldwide and higher in women, with significant cost and healthcare utilization. Given a considerable symptom overlap within the three main subtypes of constipation (namely, normal transit, slow transit, and obstructive defecation), the predominant phenotype, and the pathophysiological mechanisms are nowadays recognized by performing specialist physiologic testing, mainly consisting of colonic transit study, anorectal manometry, electromyography, balloon expulsion test, X-ray, or magnetic resonance defecography. Over the last decade, ultrasound has been advocated as a noninvasive, cost-effective, and reliable tool to be added to the inventory of diagnostic modalities. Several approaches have been described, including transperineal (or translabial), endovaginal, and transanal. Consensus exists to complement the information provided by each modality to allow an integrated assessment of the pelvic floor.