In this study, 41 randomly chosen patients aged 15 to 35 years (mean 22 years) were carefully examined. As primary operations there were 13 membrane excisions, five duodenoduodenostomies, 22 duodenojejunostomies, and one gastrojejunostomy. Twenty-eight patients were symptom-free, ten admitted some discomfort, three had major pains, including one with a history of duodenal ulcer. Reoperation for adhesion ileus had been performed in six patients, in the early postoperative phase in one instance. At late follow-up barium meals (N = 41) showed completely normal findings in two cases only, hiatal hernia in two, gastritis in three, duodenogastric reflux in 12, slight dilation of the duodenum with good emptying and no reflux in 16, a huge duodenal sac in nine, diminished peristalsis in eight, delayed emptying in five, slight luminal narrowing in three, duodenal diverticuli in nine, bezoars in two, and a polyp in the duodenum of one patient. Ultrasound (N = 35) revealed a gallbladder septum in one patient and a dilated common bile duct in another; in one subject the gallbladder was not visualized satisfactorily. Isotope biligraphy (N = 15) showed biliary reflux to the stomach in 12 cases. Endoscopy (N = 20) findings were: esophagitis (1), hiatal hernia (2), gastric mucosa in the lower esophagus (2), biliary reflux (9), gastritis (7), gastric polyps (2), dilated duodenum of variable degree (19), diminished peristalsis (4), marked retention (2), abnormal papilla (3), diverticuli (4), and a persistent membrane (1). Histology showed superficial gastritis in three patients. E coli was cultured from the duodenal juice in five patients and Candida found in two.(ABSTRACT TRUNCATED AT 250 WORDS)