Ultrasonographic assessment of liquid gastric emptying and antral motility according to the subtypes of irritable bowel syndrome in children

Gastric motor abnormalities have been reported in adults with irritable bowel syndrome (IBS), commonly in constipation-predominant IBS (IBS-C); however, such studies are uncommon in children. Furthermore, differences of gastric motility have not been studied in children with different IBS subtypes. Seventy-six children (33 [43%] boys, age 4-14 years, mean 7.9 years, SD 3.0 years) fulfilling Rome III criteria for IBS and 20 healthy controls (8 [40%] boys, age 4-14 years, mean 8.4 years, SD 3.0 years) were recruited (diarrhea-predominant IBS=21, IBS-C=31, mixed IBS=19, and unsubtyped IBS=5). Liquid gastric emptying rate (GER) and antral motility were assessed using an ultrasound method. Average GER (43.8% vs 66.2% in controls), amplitude of antral contractions (56.4% vs 89%), and antral motility index (5.1 vs 8.3) were lower and fasting antral area (1.6 vs 0.6) was higher in patients with IBS (P <0.0001). Frequency of antral contractions F (8.9 vs 9.3) did not show a significant difference. Patients exposed to stressful events had a significantly lower GER, compared to those not exposed to such events (P=0.03). Gastric motility parameters had no correlation with severity of symptoms. GER (42.6%, 46.3%, 39.6%), fasting antral area (1.4 cm², 1.8 cm², 1.8 cm²), amplitude of antral contractions (53%, 58.9%, 51.8%), frequency of antral contractions (8.7, 8.9, 9.2), and antral motility index (4.7, 5.3, 4.8) were not different among diarrhea-predominant IBS, IBS-C, and mixed IBS (P>0.05). GER and antral motility parameters were significantly impaired in children with IBS compared with controls. GER and antral motility parameters were not different between IBS subtypes