Assessing impaired gastric accommodation in children with functional constipation using the water load test

Background: This study aimed to evaluate gastric accommodation in pediatric patients with functional constipation using the water load test. Method: This was a cross-sectional case-control study. Herein, the water load test results of children aged >4 years with functional constipation referred to a Pediatric Gastroenterology Outpatient Clinic (functional constipation group) were compared with those of a control group (without functional constipation or chronic abdominal pain) recruited from two public schools. Clinical manifestations outlined in the Rome IV criteria were used to diagnose functional constipation. Water load tests were performed after 3 h of fasting. For the test, the participants were asked to drink as much water as possible in 3 min. Key Results: A total of 36 patients and 77 students were included in the functional constipation and control groups, respectively. There was no significant difference in age between the groups (8.6 +/- 2.3 years and 8.8 +/- 1.8 years in the functional constipation and control groups, respectively). The water load test showed intake volumes of 390 +/- 245 mL and 528 +/- 219 mL in the functional constipation and control groups, respectively (p = 0.001). The maximum volume in the water load test correlated with the 24 h daily intake of energy (r(S) = +0.42, p = 0.012), protein (r(S) = +0.48, p = 0.004), and water (r(S) = +0.39, p = 0.020) only in the group with functional constipation. Conclusions & Inferences: According to the water load test, gastric accommodation was impaired in children with severe functional constipation. The impairment of gastric accommodation in children with severe functional constipation is related to food intake.