Dumping syndrome following bariatric surgery: an update

Dumping syndrome refers to symptoms and signs that occur after eating in patients who have under-gone gastric bypass or gastrectomy. The symptoms can also occur as complications of oesophageal surgery and, rarely, in the absence of surgery. The prevalence of dumping syndrome after bariatric surgery varies widely, ranging from about 20% to over 75% depending on the surgery type, definition, and diagnostic criteria used. There are two main presentations: early dumping and late dumping syndrome. Early dumping syndrome comprises both gastrointestinal and vasomotor symptoms, triggered by the rapid emptying of a large amount of hyperosmolar food into the small intestine, leading to rapid fluid shifts from the plasma into the bowel and excessive secretion of gastrointestinal vasoactive peptides, causing vasodilation and increased gastric motility. This phase usually occurs within the first hour of food intake. In contrast, late dumping symptoms are of reactive hypoglycaemia due to rapid absorption of glucose, causing reactive hyperinsulinemia, which usually manifests 1-3 hours following a meal. While many patients experience mild symptoms that improve with diet, between 1% and 5% may have severe symptoms. Management of dumping syndrome often needs multiple measures. However, management can be challenging in some patients and may lead to intractable symptoms. Adopting a dumping diet is the first step in the management. Those who do not respond well to dietary modification may benefit from pharmacological treatment with acarbose or somatostatin analogues. Patients resistant to dietary and pharmacological measures may be considered for surgical intervention, but the outcome of surgery is not predictable.