A bad case of the bloat – What is chronic bloating and what can i do about it?

Posted on August 26, 2020

Have you ever gazed down to your stomach and wondered how it spontaneous ‘ballooned’ out all? Alternatively, have you ever felt as though it only takes a gulp of air to bloat you? It is important to know that you are not alone with these experiences or feelings. ‘Bloating’, or the feeling of a bursting and swollen abdomen is a common symptom of IBS.

Is some bloating normal?

Absolutely! A bit of abdominal distension is a normal part of the digestion process. Our food doesn’t just ‘disappear’ as soon as it leaves our mouths – in fact, its journey through your gastrointestinal tract has only just begun! After you eat, your stomach begins to break food down so that it can flow through to the small intestine where most absorption takes place. The breakdown of carbohydrates and fermentation of fibre produces gas, which expands and can in turn cause bloating (think of blowing air into a balloon). This bloating generally passes after a few hours and is not perceived as uncomfortable.

However, there are some cases in which people experience uncomfortable, persistent bloating that can negatively impact their quality of life. This is what we call chronic bloating.

How do you define chronic bloating?

There are two main types of chronic bloating – continuous and intermittent. Continuous bloating describes visible abdominal distention that can be measured and attributed to a specific cause. Such causes include a stomach or intestinal obstruction, obesity and/or malabsorption. Continuous bloating can also be a symptom of psychiatric conditions such as anorexia nervosa or bulimia. 1

In the case where a specific internal or psychiatric cause for bloating can’t be found, bloating is considered intermittent/functional. Functional bloating is a common symptom in patients with IBS and unlike continuous bloating, is unpredictable. People who suffer from functional bloating tend to become bloated after eating a meal or near the end of the day. 1

What is happening in my body to cause bloating?

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.

A key term to understand when explaining the cause of bloating is ‘transit time’ – which refers to the duration between when we eat a meal and when the leftover waste passes out as stool. Let’s use a sandwich for example. When you swallow a mouthful of your sandwich, it ‘boards the train’ of your gastrointestinal system. After it is mixed and grinded in the stomach, it is passed through to the small intestine where important nutrients are extracted. It is the job of the large intestine to store, process and get rid of waste, while absorbing some nutrients and water. Usually, before food (such as our sandwich), enters our large intestine, most of the nutrients have been absorbed into the body and the colon simply acts as a place for water reabsorption. However, if someone is experiencing a long transit time (the food is moving slowly through the colon), too much water is absorbed, hardening the stool and making it difficult to pass. The increased length of time during which stool remains in the colon fermenting can cause excessive pressure production in the bowel, and consequently resulting characteristic symptoms of IBS, such as bloating and excess gas production.

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 sandwich full of fibre), the abdominal wall will tighten, and the diaphragm rises into the chest so the gut contents can 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 out.

What are the foods/diets that can contribute to bloating?
Large meals:

A regular sized meal will cause a bit of routine bloating, so eating big portions is likely to cause more bloating by logic. Eating large meals activates the ‘stretch sensors’ we discussed above, which may in turn cause the diaphragm to move inappropriately and gut transit time to slow down. Instead of eating large meals, you may like to try spread out the same amount of food across the day.

Swallowing too much air:

Straws can also contribute to ingesting excess air. The build-up of air in the digestive tract can cause gas production to release the ingested air, which in turn ‘blows up the balloon’, or our stomachs in this case. In the same vein, drinking large volumes of carbonated beverages could contribute to swallowing excess air too. Polyols (the ‘p’ in FODMAP)., also known as sugar alcohols, are natural laxatives and draw water into the large intestine. They are found both naturally in fruits and vegetables such as stone fruits and mushrooms and are added to ‘sugar free’ commercial products such as mints and chewing gum. Polyols are not absorbed in the small intestine, so produce gas from the fermentation process in the colon which may contribute to abdominal bloating.

Eating too quickly & not chewing your food:

It is important to remember that our oesophagus doesn’t have teeth! Chewing helps to mechanically break down our food and this process releases digestive enzymes into our saliva. By chewing and eating at a reasonable pace rather than inhaling your food, you are doing ‘your part’ for your digestive system by giving it small chunks of food to work with and break down. A practicable strategy to reduce bloating is to make an effort to chew each mouthful of food for 30 times before swallowing.

Overdoing fermented foods and FODMAPs

Fermented foods and FODMAP containing foods are full of prebiotic fibre that our gut bacteria love. However, when eaten in excess, our gut bacteria can become ‘too excited’ and produce excess gas which leads to bloating.

What are some non-food influences that can affect bloating?


Bloating is not just a food issue – heightened stress is often a major culprit of functional bloating. Stress can put increased pressure on your abdomen which may create an environment where food that could normally be digested easily ends up being digested poorly. This may create excess gas and further ‘balloon’ out your belly. Taking up a restorative yoga or meditation practice may be helpful in slowing down and signalling to your parasympathetic nervous system that you are able to rest, digest and repair.

Hormones, particularly during your period

Have you noticed that your toilet habits may change before and during your period? There is an increase in hormones called prostaglandins that are released before your period. Think of prostaglandins as the ‘contraction’ hormone that can help the uterus shed its lining, but these contractions can also result in symptoms such as diarrhoea and bloating. The fall in progesterone a week before your period can also cause the body to retain more water and salt, causing the feeling of bloating.

Wearing tight clothes

Wearing tight pants such as jeans can give you a sense of bloating due to the pressure it places on your abdomen. As your stomach naturally contracts and relaxes throughout the day, wearing tight clothes can make this stomach movement noticeable and uncomfortable.

What can I do to reduce bloating?

Bloating reduction strategies will greatly depend on why your bloating is occurring. For example, you may find that identifying some of the common non-food influences of bloating and working to reduce the impact of these helps you immensely. For bloating causes by poor tolerance of high FODMAP foods, following the low FODMAP diet could be something to consider.

Consider following the low FODMAP diet

The low FODMAP diet temporarily restricts intake of poorly absorbed fermentable carbohydrates known to cause gastrointestinal distress. However, the low FODMAP diet is not a diet you should embark on alone, as it involves restricting FODMAP containing foods which can be found in fruits and vegetables which are known to be highly nutritious. It is important to work with a dietitian who will ensure you can meet your nutritional needs whilst also managing your functional bloating.

Reduce common trigger foods & drinks

Reducing common bloating culprits such as chewing gum, straws and carbonated beverages can go a long way to reducing your bloating. Once you have followed the low FODMAP diet and have a better idea of your dietary triggers, reducing these foods in your diet will also be helpful.

Use a heat pack or take a capsule such as Mintec

For a quick relief of abdominal pressure caused by bloating, having a lie down with a hot water bottle or heat pack across your stomach can be a great quick fix. Additionally, Mintec is a peppermint oil capsule that can provide relief of the bloating, abdominal pain, cramping and discomfort associated with IBS. Although these strategies may help in the short term, this is more of a ‘pain relief’ approach than preventative measure.

The importance of getting medical advice for chronic, continuous bloating

Above all, seeing a doctor and dietitian for chronic, continuous bloating is our key recommendation. 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.

In summary

Bloating is a normal part of digestion but can be a cause for concern if you feel as though your bloating after meals is painful and uncomfortable. The gut bacteria are responsible for producing gas as a by-product of fermentation which can go on to distend the abdomen. Dysregulated diaphragm function and increased gut transit time can also contribute to bloating. FODMAP foods tend to be gas-inducing, hence limiting the amount of FODMAPs consumed in one meal may help reduce bloating. Eating slowly, chewing well and avoiding ‘excess air gulping’ through limiting chewing gum and carbonated soft drink consumption are all additional strategies that may help.

Written by: Charlotte Barber (Student Nutritionist)
Reviewed by: Sotiria Karatsas (Accredited Practicing Dietitian)

  1. Sullivan S. N. (2012). Functional abdominal bloating with distention. ISRN gastroenterology, 2012, 721820.

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