Monosodium Glutamate on Gastric Emptying

There is evidence that monosodium glutamate has effects on synapsis at the gastric and duodenum level that results in stimulation of contractility resulting on increase rate of gastric emptying. The purpose of the study is to demonstrate that the administration of a single dose of monosodium glutamate can shorten the gastric emptying time. Patients with a prior study indicating a delay of gastric empting time, will undergo a second test with the addition of a weight adjusted dose of monosodium glutamate. Each patient will serve as her/his own control. Results will be analysed by pair-T test.