What is Dumping? And how can I prevent it?

What is Dumping? And how can I prevent it?

The dumping syndrome is when the stomach is emptied too quickly, whereby the bolus (food mass) passes into the small intestine (dumped) insufficiently digested. The food passes into the small intestine too quickly is caused by the disappearance of the reservoir function of the stomach. There are two types of dumping complaints.

Early dumping

Early dumping complaints that develop during the first hour after ingesting food or drink. They arise due to food passing into the small intestine in lumps that are too big, because the stomach has not digested the food finely enough. A poorly working pyloric sphincter in the stomach may be the cause of these complaints. The problem with early dumping is that the food in the small intestine draws an enormous amount of moisture (osmotic reaction). This can create complaints such as diarrhoea, a full feeling, nausea and stomach ache. The blood pressure also drops, because so much moisture has been drawn from the blood vessels. This causes heart palpitations, dizziness and a drowsy feeling.

Late dumping

Late dumping complaints develop around an hour and a half to two hours after ingesting food and drink. They arise because the small intestine is not yet ready for the food mush that is passed from the stomach. The food pieces are too big and pass into the intestine larger than normal because they have not been correctly digested. The digestive juices required are then insufficiently passed into the small intestine. The sugars in the food are too quickly absorbed and stimulate the production of insulin. This situation appears like a sugar deficit in people with diabetes (reactive hypoglycaemia). Among other things, this can cause complaints such as sweating, shaking, dizziness, palpitations, yawning and sometimes fainting.

Early and late dumping combined

Some people have problems with both complaint patterns, but they can also occur independently of each other. Early dumping or a combination of early and late dumping is suffered most commonly. Late dumping does not often occur by itself. The complaints arise in an attack that often occurs half an hour to an hour after the meal.


The dumping syndrome may be the consequence of an operation whereby the stomach has been partially or fully removed (stomach resection, operative reduction or gastric bypass). Sometimes the consequences arise as a result of a damaged to the nerve that controls the stomach (vagus nerve). Approximately 1% of people with the dumping syndrome have not undergone a stomach operation. Dumping complaints are therefore extremely rare in this group of people and the cause of their complaints is usually unclear.