Body composition, postprandial symptoms and social performance were studied in 61 tumor-free patients after total gastrectomy and Roux-Y esophagojejunostomy (n = 30) or jejunal interposition (n = 31). Emptying of the gastric substitute and small bowel transit of a 99mTc-labeled solid test meal were measured by scintigraphy. Serum glucose levels, and immunoreactive insulin were measured simultaneously. The lowest postoperative weight was 73 +/- 2% of the pre-morbid weight in Roux-Y cases, and 77 +/- 2% after jejunal interposition, the weight at study was 82 +/- 2% respectively 87 +/- 1% of the premorbid weight (p less than 0.05). Of the patients younger than 60 years at operation only one third of the twelve Roux-Y cases had resumed their work, as compared to two thirds of the eighteen interposition cases (p = 0.056). The incidences of the postprandial symptoms were not different among the modes of reconstruction, except for a slightly higher incidence of late dumping in Roux-Y (17% vs. 10%). After correction for gender higher mean values of fat-free mass, total body water, and intracellular water were measured in interposition cases (bioelectric impedance analysis). The emptying half-time of the gastric substitute was 488 s in the Roux-Y group, and 378 s after interposition (p = 0.05), whereas the small bowel transit (median: 200 min) showed no differences between the groups. There was no correlation between t1/2 or small bowel transit and the nutritional data. Early dumping (p = 0.01) was the only symptom significantly associated with rapid emptying of the gastric substitute.(ABSTRACT TRUNCATED AT 250 WORDS)