13 January 2021

Section 15: Dumping Syndrome


What is dumping syndrome?


Dumping syndrome or rapid gastric emptying is relatively common following bariatric surgery procedures that alter the gastric anatomy, such as sleeve gastrectomy and gastric bypass. Dumping syndrome occurs when food, especially sugary and starchy food moves too quickly through the stomach in to the duodenum (the first part of the small intestine). Additionally, if a large volume of fluid is consumed with a meal this can cause dumping syndrome. It affects up to 50-70% of patients in the first 15-18 months after surgery, although only 1-5% have symptoms that they find disabling. 


Dumping syndrome is not a single disease entity, but instead consists of a collection of predominantly gastrointestinal symptoms that can be classified as either early or late dumping symptoms. It occurs less often as time passes.


Early dumping syndrome


Early dumping syndrome is the most common type of dumping syndrome and may occur in isolation or in association with late dumping symptoms. It usually occurs within 30 minutes of eating. Early dumping syndrome symptoms are the result of the rapid delivery of food in to the small intestine due to the reduction in gastric volume from surgery.


The food is more concentrated so fluid moves from the bloodstream into the intestines. The movement of fluid can cause distension which may result in cramping, bloating and, diarrhoea up to 60 minutes later. Some substances, including hormones, are released by the small intestines that affect heart rate and blood pressure.


Symptoms vary from one individual to another but can include:


  • Bloating
  • Sweating
  • Abdominal cramps and pain
  • Nausea
  • Facial flushing
  • Dizziness and feeling faint or fainting (syncope)
  • Heart palpitations and rapid heart rate
  • Stomach growling or rumbling (borborygmi)
  • An urge to lie down after a meal
  • Diarrhoea



Late dumping syndrome


Late dumping syndrome symptoms can occur one to three hours after eating a meal containing carbohydrates. The rapid delivery of sugars to the intestine increases the body’s glucose levels causing a response of the pancreas to release insulin (also known as reactive hypoglycaemia). In late dumping syndrome, the increased release of insulin causes a rapid drop in blood glucose levels to lower than what is considered normal, resulting in a condition known as reactive hypoglycaemia (low blood glucose level).


Symptoms vary from one individual to another but can include:


  • Sweating
  • Hunger
  • Fainting
  • Fatigue
  • Heart palpitations or rapid heart rate
  • Tremors
  • Confusion
  • Aggression



How to avoid dumping syndrome


To avoid experiencing dumping syndrome you can:


  • Eat smaller meals more frequently, i.e. 5 to 6 small meals per day instead of 3 larger meals
  • Maintain a balanced diet and focus on protein and lower glycaemic index foods
  • Reduce the intake of sugary foods including sweets, chocolate, cakes and biscuits
  • Limit the intake of sugary drinks including fruit juices, sugar in hot drinks and full-sugar cordial. Choose sugar-free cordial, no-added-sugar flavoured water and use artificial sweetener instead of sugar in hot drinks, e.g. Candarel, Splenda, Sweetex and Stevia.
  • Eat slowly and avoid rushing meals
  • Avoid drinking liquids during and for 60 minutes after eating. Drinking with a meal can flush food through the stomach and in to the small intestine quicker, which increases the risk of dumping syndrome and reduces satiety, making you more likely to overeat.


Glycaemic Index


The Glycaemic Index (GI) is a ranking of carbohydrate-containing foods based on the extent to which they raise blood glucose levels after consumption. Foods with a high GI are rapidly digested and can cause sudden spikes in blood glucose levels. Foods with a low GI prevent peaks in blood glucose levels as they are digested more slowly. Choose lower GI foods to help prevent dumping syndrome as the blood glucose levels will not rise as quickly as higher GI foods.


Examples of low GI foods:



  • All bran
  • Oat bran
  • Natural muesli (no added sugar)
  • Porridge and rolled oats



  • Soya and Linseed
  • Wholegrain/Pumpernickel
  • Sourdough rye


Fruit and Vegetables

  • Cherries
  • Plums
  • Peaches
  • Apples
  • Grapes
  • Strawberries
  • Coconut
  • Peas
  • Carrots
  • Aubergine
  • Broccoli
  • Tomatoes
  • Lettuce
  • Red pepper
  • Onions
  • Mushrooms
  • Cauliflower




  • New potatoes/sweet potatoes
  • Brown rice
  • Spaghetti/noodles
  • Butter beans/chickpeas
  • Hummus
  • Lentils
  • Whole/skimmed milk
  • Soy milk
  • Cashews and peanuts


Examples of medium GI foods:



  • Weetabix
  • Shredded wheat




  • Croissant
  • Pitta bread
  • Whole meal rye
  • Ryvita



Fruit and Vegetables

  • Beetroot
  • Mango
  • Sultanas
  • Bananas
  • Figs
  • Pineapple



  • Basmati rice
  • Couscous
  • Cornmeal
  • Gnocchi
  • Canned potatoes
  • Vermicelli rice noodles
  • Baked potatoes
  • Wild rice
  • Beans in tomato sauce
  • Ice cream





Examples of high GI foods:



  • Cornflakes and those coated in honey
  • Branflakes
  • Puffed rice
  • Instant oatmeal



  • White bread
  • Bagels
  • French baguette
  • Pretzels
  • Rice cakes
  • Popcorn


Fruit and Vegetables

  • Melon
  • Dates
  • Pumpkin
  • Parsnips



  • Instant white rice
  • Tapioca
  • Mashed potatoes
  • Frozen chips
  • Donuts
  • Sugary drinks



However, there are a few factors that affect the GI of a food including:


  • Ripeness – the more ripe a fruit or vegetable is, the higher the GI
  • Cooking – how the food is cooked, e.g. al dente pasta has a lower GI than soft-cooked pasta, and mashed potato has a higher GI than boiled new potatoes
  • Fat – fat lowers the GI of a food. Chocolate is therefore lower GI but ensure your overall diet is still low in fat to promote weight loss
  • Protein – protein lowers the GI of a food so make sure each meal contains some protein, e.g. dairy products, chicken, fish, meat, beans or pulses
  • Wholegrains – wholegrains and high-fibre foods help slow down absorption of glucose into the blood stream, e.g. wholegrain breads have a lower GI than wholemeal or white bread


Treating dumping syndrome


If you experience dumping syndrome the best thing you can do is lie down and rest – the symptoms should eventually resolve. Try and identify what it was you ate or drank that caused it so you can prevent it from happening again.


Some patients (about 1%) are affected by dumping syndrome to the point where further treatment (medication or surgery) is needed. Your dietitian will refer you to your surgeon if they feel your symptoms are not being managed effectively via dietary changes alone.




You must be over 18 in order to browse this site

Leave site
Book a free consultation

Price Check

book your free consultation