[Behavior of the serum electrolytes after jejuno-ileal bypass for obesity].

Serum electrolytes, diarrhoea and absorption of bile salts were examined before and for one year after jejuno-ileal by-pass in 5 obese subjects. Marked decrease in blood potassium, calcium and magnesium was noted post-operatively, with potassium and calcium levels still well below the preoperative levels after 1 yr. Faecal volume increased considerably soon after operation, then fell to about 1 1/day in the first few months and changed little thereafter. Absorption of bile salts was seriously and lastingly compromised. In the light of the relevant literature, these results show that electrolyte imbalance, being closely linked to diarrhoea induced by bile salts, is an inevitable consequence of this operation and cannot be controlled by changing the surgical procedure.