Although relatively frequent. diabetic involvement of digestive tract motility has not been investigated extensively in different organs. The authors studied esophageal, gastric, and gallbladder motor function in 35 type 2 (noninsulin-dependent) diabetic patients to determine the extent of gut involvement. Of these patients, 27 (77%) had peripheral neuropathy, 12 (34%) had both peripheral and autonomic neuropathy, and 22 (63%) had gastrointestinal symptoms. Esophageal manometric abnormalities were recorded in 18 patients, and delayed radionuclide emptying of the esophagus was documented in 16 patients, with a 83% concordance between the two tests. Scintigraphic gastric emptying of solids was delayed in 56% of patients, whereas gallbladder emptying after cholecystokinin stimulation was reduced in 69% of them. In 74% of patients at least one of the viscera under investigation showed abnormal motor function; however, only 36% of patients displayed involvement of the three organs. Gastrointestinal symptoms, duration and therapy of diabetes, previous poor glycemic control, and retinopathy did not correlate with the presence or the extent of motor disorders. Neuropathy was not predictive of gastrointestinal involvement and its extent; however, when motor abnormalities were present in patients with neuropathy, these were usually more severe. Gastrointestinal motor disorders are frequent and widespread in type 2 diabetics, regardless of symptoms. Autonomic neuropathy has a poor predictive value on motor disorders (0.75 for the esophagus, 0.5 for the stomach, 0.8 for the gallbladder), thus suggesting the coexistence of other pathophysiologic mechanisms.