Bloating Symptoms following High FODMAP Food Consumption

‘Bloating’, or the feeling of a bursting and swollen abdomen is a common symptom of IBS.

Our intestinal organs are very clever and have ‘stretch sensors’ in their muscular wall that are able to sense when the organ is distended. People with IBS tend to have particularly sensitive stretch sensors. When these sensors feel over stretched, our body may interpret this as bloating.

Let’s now have a look at what is happening in your body to cause bloating at each step of the digestion process. Imagine you’ve eaten a big Mexican burrito bowl: corn, black beans, kidney beans, onion and garlic topped with sour cream and cheese. There are a few different FODMAPs (namely fructans, GOS and lactose) going on in this dish!

When you swallow a mouthful beans and onion, it ‘boards the train’ of your gastrointestinal system. After this is mixed and grinded in the stomach, it is passed through to the small intestine where important nutrients are extracted. Carbohydrates are broken down to sugars to be absorbed into the blood stream.  However, some carbohydrates, known as FODMAPs are unable to be absorbed in the small intestine for some individuals.

It is the job of the large intestine (also known as the colon) to process and get rid of waste, while absorbing some nutrients and water. Usually, before the remnants of our food mixture enters the large intestine, most of the nutrients have been absorbed into the body.  The large intestine simply acts as a place for water reabsorption. However, if the food particles (like particles from those beans and onions you ate) are moving slowly through the colon, too much water is absorbed.  With less water in the large intestine, the stool can harden and become more difficult to pass.  This can leave the stool to ‘hang out’ for longer in the large intestine, where the food particles continue to ferment and produce excessive gas and pressure in the bowel.  Consequently, this results in bloating and excess gas production (wind), which are characteristic symptoms of IBS.

The gut wall is also lined with nerves which can be more sensitive in people with IBS.  When the gut stretches from increased pressure, the nerves in our gut tend to overreact.  This leads to a feeling of discomfort and pain in the abdomen.

When the nerves in our gut overreact to being stretched, our level of discomfort increases. Usually, when a person eats a meal that causes some gas production (such as a burrito bowl full of fibre), the abdominal wall tightens, and the diaphragm rises into the chest making room for the gut components to stretch out a bit more. However, in people who suffer from chronic bloating, the diaphragm unfortunately likes to do the opposite – it pushes down, which causes the abdomen to bulge.  Hence, we see a more bloated belly.

The importance of getting medical advice for chronic, continuous bloating

It is important to see a Doctor and Dietitian for chronic, continuous bloating. Chronic bloating could be a result of more sinister conditions such as bowel obstructions or bowel cancer, and your Doctor can help you address the root cause of the problem.

A FODMAP-specialised Dietitian is a great person to have on your IBS management team. A Dietitian can perform a full patient assessment, including a symptom assessment and diet history. They will be able to answer all of your FODMAP questions, and help you choose the best course of action when it comes to the way in which you’d like to implement the diet. Also, there is greater risk of nutritional inadequacy when eating low FODMAP which could lead to nutritional deficiencies in the long term. Dietitians will help ensure that you are meeting all of the nutritional requirements when eating low FODMAP.

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Charlotte Barber (Nutritionist), Rebecca Ponsford and Kiarra Martindale (Accredited Practising Dietitians)