Billroth II procedures (gastrojejunostomy with vagotomy) are seldom performed now but were popular before the advent of histamine 2 receptor blockers and proton pump inhibitors. Such procedures can be a cause of late postprandial hypoglycemia.

We performed a formal evaluation and discussion of postprandial hypoglycemia.

We present a case of an 85-year-old man who presented to the endocrinology clinic with symptoms of “fainting spells after large meals.” The patient previously had extensive evaluations by a neurologist and a cardiologist. Because of the history of Billroth II surgery and the description of his fainting spells, a 5-hour glucose tolerance test was performed in the clinic using the foods that uniformly resulted in symptoms. This confirmed that the late dumping syndrome with associated hypoglycemia was the cause of his spells.

Late dumping syndrome manifesting with hypoglycemia should be considered in the workup of patients with a history of gastric surgery and unusual postprandial symptoms. This case highlights the importance of an appropriate workup that can lead to avoidance of unnecessary testing in such patients.