In 65 jejunolleal (JI) bypasses done from 1973-1979, there were nine Scott and 56 Payne (with Y-shaped anastomosis). Preoperative excess body weight (EBW) translated to the 1983 Metropolitan Tables was 112 +/- 30%. Eight patients are lost to follow-up. We reversed seven patients for renal stones (12%) accompanied by a vertical banded gastroplasty (VBG) and one because she demanded a VBG. Five patients were reversed by surgeons elsewhere for minor problems (three with an accompanying gastric reduction operation), and all five regained and requested a JI bypass again, which we now refused to undertake. This leaves 44 JI bypass patients being followed: loss of EBW is 71 +/- 22% at 12-18 years. The eight reversed by us accompanied by a VBG regained some weight (loss of EBW from initial weight is 56 +/- 18%). Liver biopsies were done for 5 years in 31 patients, and showed improvement by 36 months. Patients took predigested collagen capsules plus high protein and multivitamins. Injections of B12 are indicated in 18 patients, given every 3 months. Liver dysfunction has not occurred in the long-term. Low serum carotene levels persist. Migratory arthraigias were controlled by oral metronidazole and did not occur after the fifth year. Oxalate crystals remain on urinalysis. Potassium and magnesium replacement is not required now, and a mean of 2.5 stools per day is not a problem, with infrequent diarrhea after greasy foods. Metronidazole is continued in 33 patients to prevent foul flatus. One patient developed a brain tumor, one myxedema, and one primary hyperparathyroidism, thought to be complications of the bypass until diagnosed. Most patients appear to be doing well.