Figure 1:

Flow diagram showing participant selection. *History of abdominal disorder included abdominal surgery (n = 167), abdominal trauma within 48 hours (n = 42), cyclic vomiting (n = 24), celiac disease (n = 18), hepatobiliary disease (n = 14), bowel obstruction (n = 13) and chromosomal abnormality affecting abdominal viscera (n = 12). †Underlying medical conditions included congenital renal anomaly (n = 55), congenital genitourinary anomaly (n = 53), inflammatory bowel disease (n = 37), pelvic inflammatory disease (n = 3), neutropenia (n = 1) and tuberculosis (n = 1). Note: HBB = hyoscine butylbromide.