Dumping syndrome is a condition that can develop after surgery to remove all or part of your stomach or after surgery to bypass your stomach to help you lose weight. Most people with dumping syndrome develop signs and symptoms, such as abdominal cramps and diarrhea, 10 to 30 minutes after eating. After gastric surgery, it can be more difficult to regulate movement of food, which dumps too quickly into the small intestine. An early dumping phase may happen about 30 to 60 minutes after you eat. Symptoms can last about an hour and may include a feeling of fullness, even after eating just a small amount, abdominal cramping or pain, nausea or vomiting, severe diarrhea sweating, flushing, or light-headedness and rapid heartbeat. A late dumping phase may happen about 1 to 3 hours after eating.