Copyright: ©Author(s) 2026. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial (CC BY-NC 4.0) license. No commercial re-use. See permissions. Published by Baishideng Publishing Group Inc.
World J Clin Pediatr. Dec 9, 2026; 15(4): 119251
Published online Dec 9, 2026. doi: 10.5409/wjcp.119251
Published online Dec 9, 2026. doi: 10.5409/wjcp.119251
Rectal diameter measured by transabdominal ultrasonography for monitoring treatment response in children with functional constipation
Duc Long Tran, Nitikarn Pinyoying, Palittiya Sintusek, Center of Excellence in Thai Pediatric Gastroenterology, Hepatology and Immunology, Division of Gastroenterology, Department of Pediatrics, Faculty of Medicine, King Chulalongkorn Memorial Hospital, Chulalongkorn University, Bangkok 10330, Thailand
Duc Long Tran, Faculty of Medicine, Can Tho University of Medicine and Pharmacy, Can Tho 90000, Viet Nam
Author contributions: Tran DL and Sintusek P conceptualized, designed the methodology, and performed the research; Tran DL, Pinyoying N and Sintusek P collected data; Tran DL analyzed the data and wrote the original draft; Sintusek P validated the results and made critical revisions; all authors have read and approved the final manuscript.
Supported by Chulalongkorn University, the Second Century Fund, No. C2F; and Thailand Science research and Innovation Fund Chulalongkorn University, No. HEA_FF_69_225_3000_031.
Institutional review board statement: This study was approved by the Institutional Review Board of Chulalongkorn University (No. 0093/67).
Clinical trial registration statement: This study is registered at ClinicalTrials.gov. The registration identification number is NCT06357897.
Informed consent statement: All study participants provided informed written consent prior to study enrollment.
Conflict-of-interest statement: The authors declare no conflict of interest regarding this study.
CONSORT 2010 statement: The authors have read the CONSORT Statement—checklist of items, and the manuscript was prepared and revised according to the CONSORT Statement—checklist of items.
Data sharing statement: Technical appendix, statistical code, and data set available from the corresponding author at
Corresponding author: Palittiya Sintusek, MD, PhD, Associate Professor, Center of Excellence in Thai Pediatric Gastroenterology, Hepatology and Immunology, Division of Gastroente
Received: January 26, 2026
Revised: February 6, 2026
Accepted: March 6, 2026
Published online: December 9, 2026
Processing time: 240 Days and 2.2 Hours
Revised: February 6, 2026
Accepted: March 6, 2026
Published online: December 9, 2026
Processing time: 240 Days and 2.2 Hours
Core Tip
Core Tip: Although transabdominal ultrasonography (USG) has been increasingly employed to assess fecal impaction in children with functional constipation (FC), evidence supporting its role in monitoring treatment responses remains limited. In this prospective substudy of a randomized controlled trial evaluating the efficacy of commercial polyethylene glycol (PEG) and PEG-Chula, USG-measured rectal diameter (RD) exhibited a significant decrease after 8 weeks of treatment, paralleling clinical improvement. In contrast, anterior rectal wall thickness did not change significantly during treatment. These findings indicate that USG-measured RD may be a practical, noninvasive parameter for monitoring treatment response in children with FC.