“Dumping syndrome occurs when food, especially sugar, moves too fast from the stomach to the duodenum—the first part of the small intestine—in the upper gastrointestinal (GI) tract. This condition is also called rapid gastric emptying. Dumping syndrome has two forms, based on when symptoms occur:

• early dumping syndrome—occurs 10 to 30 minutes after a meal
• late dumping syndrome—occurs 2 to 3 hours after a meal”

NIH National Institute of Diabetes and Digestive and Kidney Disease