Gastric compliance in bulimia nervosa

Bulimia nervosa (BN) is a psychiatric illness characterized by eating binges followed by inappropriate behavioral attempts to compensate for the binges, usually vomiting or laxative abuse. Patients with BN have disturbances in the development of satiety during a meal as well as disturbances in functions of the upper gastrointestinal tract such as slowed gastric emptying, impaired gastric accommodation reflex and blunted cholecystokinin release. The present study examined gastric compliance and sensory responses to gastric distention in women with BN and controls. Sixteen women with BN and 13 healthy control subjects swallowed an inflatable bag that was placed in the proximal stomach. The bag was inflated to produce increasing steps of pressure against the stomach wall, before and after consumption of a 200 ml (200 Kcal) liquid meal. Pressure and volume were recorded for 2-min periods, beginning at 0 mm Hg pressure and increasing in steps of 2 mm Hg until subjects reported discomfort, gastric volume reached 600 ml, or pressure reached 20 mm Hg. At each pressure step subjects made sensory ratings. Gastric compliance was calculated as the slope of the best-fit straight line of each subject's gastric volume vs. gastric pressure. There was a significant postmeal increase in gastric compliance in both groups of subjects but there was no difference in compliance between patients with BN and controls. Patients with BN appeared to have diminished sensitivity to gastric distention. In conclusion, although other studies have described gastrointestinal abnormalities associated with BN, the current study found gastric compliance of patients with BN to be normal.