We describe a case of acute autonomic neuropathy in an 18-year-old woman. Gut dysfunction was sufficiently severe for the patient to undergo laparotomy for suspected mechanical-intestinal obstruction before the diagnosis was made. Apart from the gut, other organs affected included the pupils, sweat and lachrymal glands. Cardiovascular autonomic function tests showed the involvement of sympathetic adrenergic nerves. Small bowel barium X-ray showed resolution of gastric stasis and emergence of jejunum dilatation during intravenous administration of erythromycin but this treatment did not eliminate intestinal obstructive symptoms. The patient had an incomplete recovery in 3 months. Erythromycin might have therapeutic value in patients with intestinal motility dysfunction in acute dysautonomia.