Gastroesophageal reflux in children: evaluation of the water siphon test.

Fifty-nine symptomatic children were radiologically evaluated for gastroesophageal reflux with the water siphon test and also with the acid reflux test and esophageal manometry. Of those with reflux on pH testing, 95% had positive water siphon tests, and 38% also had spontaneous barium reflux. Of those with negative acid reflux tests, 29% had positive water siphon tests. Lower esophageal sphincter pressure did not correlate with either test unless the pressure was less than 10 mm Hg. Barium esophagography with the water siphon test is the appropriate initial examination in symptomatic patients, but the false-positive rate is high.