36. ANORECTAL FUNCTIONAL ASSESSMENT IN CHILDREN WITH REFRACTORY CONSTIPATION: A CROSS-SECTIONAL STUDY AT CHILDREN’S HOSPITAL 2, HO CHI MINH CITY. YHCĐ. 2025;66(CĐ16-HNKH Bệnh viện Nhi Đồng 2). doi:10.52163/yhc.v66iCD16.3348