A previous study has demonstrated that symptoms suggestive of dumping syndrome appear after a provocation test early after laparoscopic sleeve gastrectomy (LSG) in 45 % of patients, and these are mainly related to early dumping. The aim of this study is to evaluate the evolution of dumping symptoms during the first postoperative year.

Twenty-five non-diabetic morbidly obese patients (6 male, 19 female) were evaluated with an oral glucose tolerance test (OGTT) preoperatively, at 6 weeks and at 6 months postoperatively. In addition, 12 of them repeated the OGTT at 12 months after LSG. Sigstad score was used to separate dumpers from non-dumpers and Arts’ questionnaire to differentiate between early and late dumping. Insulin and glucose levels were also measured.

Sigstad score remained significantly elevated at 6 and 12 months postoperatively compared to preoperative values. Symptoms suggestive of dumping syndrome were recorded in 40 % of patients at 6 months and in 33 % at 12 months postoperatively. Arts’ questionnaire demonstrated that early dumping score remained higher compared to baseline at 6 and 12 months postoperatively. Late dumping scores increased gradually during the time and that difference was statistically significant at 12 months after LSG. Hypoglycaemia occurred at 33 % of patients both at 6 and 12 months postoperatively.

Symptoms suggestive of dumping syndrome after provocation still exist at 6 and 12 months in a significant proportion of patients after LSG and include both early and late dumping. These findings are consistent with the high incidence of hypoglycaemia after OGTT at 6 and 12 months after LSG.