Usefulness of ultrasound in diagnosing constipation in children: a narrative review.

Chronic constipation in children is a significant problem not only for the child but also for the family and caregivers in institutional settings. Constipation is a common clinical symptom, accounting for nearly one-third of consultations in pediatric gastroenterology clinics. In the vast majority of cases, the cause is functional constipation, whose pathogenesis is complex but usually benign. The greatest challenge lies in identifying organic causes within this patient group, for which ultrasound is particularly well suited as a non-invasive tool for exclusion. Transabdominal intestinal ultrasound is an ideal diagnostic tool due to its non-invasive, cost-effective, and repeatable nature, and its ability to be performed during routine outpatient visits. It enables objective assessment of fecal retention by measuring rectal diameter (RD), rectal wall thickness, and degree of colonic filling. In addition, ultrasound may be useful for assessing stool consistency and colonic transit. Perianal ultrasonography is a complementary method to transabdominal intestinal ultrasound, enabling a more detailed evaluation of anal canal structures. Ultrasound may therefore represent a valuable adjunct in the diagnosis and management of pediatric constipation, although further standardization of methodology and diagnostic criteria is required.