Gastroduodenal manometry is a test of the pressure changes which occur within the stomach and upper intestine during digestion. The test is similar to esophageal manometry, but takes longer and requires some sedation because of the manipulation.
The pressure-sensitive plastic tube is placed with an endoscope which is passed into the small intestine (upper endoscopy). The position of the manometry testing tube is checked with X-ray, and the endoscope is removed. The tube is left coming out through the nose for one or two hours.
The tube is connected to a computer which detects and analyzes the muscular contractions. These are tested in the resting state, and after a small, standard meal. After the test, the tube is gently removed.