At one time or another, you’ve probably felt bloated, which is the uncomfortable sensation of having trapped gas or increased pressure or fullness in your gut. It may or may not be accompanied by a visibly distended (swollen) abdomen.

Firstly, it’s perfectly normal to experience bloating sometimes. However, this isn’t to say that bloating is something to be ignored. The feelings of bloating can range from mildly uncomfortable to intensely painful. And it usually goes away after a while, but for some people, it’s a persistent issue, bothersome and negatively affect their daily lives. In some people, bloating may also be accompanied by other symptoms such as nausea, vomiting, constipation/diarrhoea/changes in the bowel movements, and weight loss. While the economic impact of chronic bloating and distensions has not been well studies, 50% of people with bloating reported that their symptoms cause a reduction in daily activities (link).

What makes us feel bloated?

The most common cause of abdominal bloating is excess gas in the intestines. If you get a bloated belly after eating, it could be due to simple things like eating too much too fast or due to a food sensitivity or other conditions that cause gas and digestive contents to build up. Abdominal bloating can also develop as a result of a previous infection that perturbed the intestinal microbiota (gut microbial dysbiosis), disordered visceral sensation or because of an delayed intestinal transit. (link)

How common is abdominal bloating?

  • About 16% – 31% of otherwise healthy people complain of occasional abdominal bloating.
  • As many as 75% describe their symptoms as moderate to severe and about 10% say they experience it regularly.
  • As high as 66% – 90% of those diagnosed with irritable bowel syndrome (IBS) are thought to experience bloating.
  • Only 50% – 60% of people who experience bloating also report abdominal distention. (link)

What causes abdominal bloating?

1. Gas

The most common form of bloating is due to gas. Gas in the gut can come from various sources. The 5 most common gases found in the gut are Nitrogen (N2), Oxygen (O2), Hydrogen (H), Carbon dioxide (CO2), and methane (CH4). Nearly all N2 and O2 in the upper part of the gut comes from swallowing air. CO2 in the gut comes from swallowed air, drinking carbonated beverages or from diffusion from the bloodstream into the gut. While you can ingest gasses by swallowing air or drinking carbonated beverages, these gasses mostly escape through belching before they reach your intestines. CO2 gas can also be generated from acids and alkalis in the upper gut after eating food.

Carbohydrate malabsorption: Gasses in our lower intestines are mostly produced by gut bacteria digesting carbohydrates in the food, in a process called fermentation. Most carbohydrates in our diet once broken down can be absorbed through the cells in your small intestine. There are some carbohydrates that are incompletely or not digested at all within the small intestine and therefore can’t be absorbed. These rapidly fermentable short chain carbohydrates that can’t be digested in the small intestine are called FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols). The presence of FODMAPs causes the water to be dragged into the small intestine and when FODMAPs arrive in the colon, the resident colonic bacteria can utilise FODMAPs for energy to fuel the cells that line the colon. The colon bacteria rapidly ferment FODMAPs and produce gas. It is the excess gas production and water retention that causes the intestines to expand leading to sensation of bloating and distension in certain people. Many people have difficulties digesting FODMAP carbohydrates and as a result, experience symptoms like bloating, gas, constipation, and diarrhoea. Following Low FODMAP diet has been shown to benefit bloating and other symptoms in people with IBS. It does makes sense that avoiding some types of foods such as these FODMAP foods can reduce gas production and therefore bloating.

The amount of the gas produced in the colon depends on several factors:

  • the type and number of bacteria in the colon
  • the speed of food moving through the intestines
  • the types of foods being consumed
  • the rate of fermentation in the colon

Visceral sensitivity: Another important element in causing the symptoms of bloating is the visceral hypersensitivity. Some people feel like they are gassy and bloated even when their volume of gas is normal (link). This condition often correlates with IBS and other disorders involving the gut-to-brain neural pathway (link). When the intestinal wall stretches from distention the highly connected nerves around the intestines send the signals to the brain. People with IBS often have hypersensitivity, and this means that ordinary small changes in the volume of the gut can be perceived as bloating. Some very sensitive people might perceive the sensation of bloating without any volume change in the gut whatsoever. In fact, they can perceive bloating in response to normal contraction of the gut (link).

Furthermore, stress, anxiety, high fat meals, weight gain, and changes during the menstrual cycle are linked to bloating (link). Some people also experience bloating due to muscle reflexes in the abdominal wall and diaphragm (link).

2. Digestive Contents

Gas production is not the only explanation of why a person can experience bloating. Bloating can sometimes be caused by build-up of digestive contents (solids, liquids and gas) in your digestive system when there is a backup or restriction in your digestive system or due to abnormal peristalsis where the muscle that moves the digestive contents along are somehow impaired. So, any build-up of digestive contents along the digestive tract will leave less room for normal amounts of gas to process through.

Moreover, certain types of food can also influence retention of gas. For example, fats classically can cause retention of gas in the first part of the small bowel. Additionally, some people can’t evacuate gas very well and that can cause in retention of gas in the colon and therefore symptoms of bloating and abdominal pain.

People suffering from functional chronic constipation are known to be less able to evacuate gas from the rectum and thus are much more likely to develop symptoms of abdominal distention. If the gaseous content of the gut increases, then the abdomen can expand thus increasing the abdominal pressure. Backed-up poop in your colon causes recently digested food to stay longer in the intestines, waiting to descend. Everything expands to contain the extra volume, leading to bloating.

What can relieve bloating?

⚠DISCLAIMER⚠ This article is for information only. It is not intended to constitute or be a substitute for professional medical advice, diagnosis, or treatment. Always consult a healthcare professional if you suspect a food intolerance and before removing food groups from your diet. Changes in eating habits should be overseen by registered healthcare professionals who are qualified to guide patients in the correct application and implementation of diets by tailoring for your individual circumstances.

Below are few things that might help with bloating:

  • As bloating is triggered by many dietary, lifestyle and health factors, it is most practical to identify the cause in order to reduce or resolve symptoms.
  • Limit foods that trigger bloating. Keeping a food diary may help you identify which foods cause your symptoms so that you don’t have to follow an overly restrictive diet.
  • Check for food sensitivities and food intolerances. Lactose intolerance for instance is a common condition that causes multiple digestive symptoms including bloating.
  • Support regular bowel habits to alleviate constipation. Increasing your dietary fibre intake, drinking adequate fluids and exercising regularly helps keep your bowels regular.
  • Feed your gut microbiome with prebiotic fibres to keep your gut health in top shape. It is important to note that tolerance to certain prebiotics (particularly those that tend ferment rapidly in the gut) may vary from person to person. Prebiotics with ability to ferment at a slower rate or at a uniform rate like virgin sugarcane prebiotic – Kfibre.
    • Kfibre is a natural whole-plant Virgin Sugarcane prebiotic that is uniformly fermented along the gut meaning it supports healthy digestion while producing less gas in the process, making it microbiome supporting & well tolerated. Plus, Kfibre in addition to being rich in prebiotic fibre, also carries other inherent phytonutrients.

The best prebiotics are plants because they come neatly packaged up with other phytochemicals, like antioxidant polyphenols and phytonutrients like vitamins and minerals that are essential for the body.

If you do need a little help in meeting your daily recommended dietary fibre intake or support for digestive health, try our KfibrePro Dietary Indigestion & Bloating. It is a Low FODMAP accredited synbiotic that is formulated to support normalisation of bloating, gas & indigestion.

If you are experiencing persistent bloating, it is important to talk to a healthcare professional who can help identify the cause of your bloating. To ensure that your nutrient needs are met and determine your individual circumstance its best to work with a registered dietitian when making significant changes to your diet.


By Dr Tanvi Shinde, PhD