Why do I bloat? 5 reasons for gut problems most doctors ignore

One of the most Googled online health searches  is ‘why do I bloat?’ Jo Waters,  co-author of What’s Up With Your Gut? a new book on mystery gut conditions,  reveals what could be causing your embarrassing symptoms

It’s a mystery that has puzzled gastroenterologists for years – just why do so many patients complain of bloating after eating bread and pasta? Can they really all have coeliac disease or is there something else going on?


What’s coeliac disease and how do you know if you’ve got it?

Coeliac disease is an autoimmune condition where the body mistakes gluten, a protein found in wheat , barley and rye for a pathogen and produces antibodies to attack them. It is estimated to affect one per cent of the population but an estimated three quarters of all coeliacs remain undiagnosed (that’s around 500,000 people in the UK) and researchers from Nottingham University have found it takes an average of 13 years to get a diagnosis.

Coeliac disease is an autoimmune condition where the body mistakes gluten, a protein found in wheat , barley and rye for a pathogen and produces antibodies to attack them

Apart from causing short term symptoms which include  bloating, diarrhoea, stomach cramps, constipation, sudden weight loss and flatulence, undiagnosed coeliac disease makes absorption of nutrients difficult and can lead to long term complications, including anaemia and tiredness, osteoporosis, unexplained infertility and a slightly higher risk of developing certain cancers and lymphomas, if left  untreated.

Part of the problem is that the symptoms of coeliac disease can vary, be mild or severe and be easily confused with other conditions such as Irritable Bowel Syndrome unless the right tests are done. Non-gut symptoms are vague and include mouth ulcers, headaches, tiredness and fatigue, iron deficiency anaemia and short stature in children and are all common conditions in their own right.

some people with coeliac disease have no symptoms

To complicate matters even more, some people with coeliac disease have no symptoms at all and if they are diagnosed at all its usually through routine screening because a close family member has been diagnosed. The standard tests recommended are a blood test for antibodies and a biopsy to check for damage to villi, tiny finger like projections that line the gut that absorb nutrients. If the villi are damaged that is confirmation of coeliac disease.


Once diagnosed though, following a gluten-free diet should in the vast majority of cases make symptoms disappear. If gluten is avoided, the body won’t mount an antibody response , the gut villi will heal and most people can live a normal life untroubled by gut problems. Flare ups only happen if they accidentally eat gluten – even a tiny amount can cause a reaction, so it can be difficult to avoid, particularly when eating out when there’s a risk of cross contamination in restaurant kitchens.

Could you have non-coeliac gluten sensitivity (NCGS)?

In the old days, if you had negative biopsy results you would have probably been told you didn’t have coeliac disease and advised wheat was not to blame for your symptoms and was safe for you to eat.

These days though there’s wider recognition of another condition called non coeliac gluten sensitivity (NCGS) – this is where you have the symptoms of coeliac disease but it doesn’t appear to involve the immune system, so no antibodies show up in blood tests and the villi in the gut appear normal. Crucially though , the symptoms of NCGS appear to go away if patients follow a gluten-free diet.

MORE: Do you really need to give up gluten?

Not all doctors believe NCGS exists as a well- defined separate condition – mainly because no-one understands what causes it and there is no diagnostic test for it as yet, but also because it’s possible that symptoms get better because of the placebo effect. Others say there’s considerable overlap with IBS. But NCGS is now gaining wider acceptance, mainly due to a flurry of new research in the last three years – and doctors say this has been driven by patients.  Gastroenterologists say they have seen pictures of their patients’ bloated bellies photographed on mobile phones shortly after eating gluten, for instance and patient forums on the internet are abuzz with NCGS too, with people comparing their symptoms and solutions  they have come up with.


In November 2012  gastroenterologist Dr Kamran Rostami wrote an article in the British Medical Journal describing a patient who had been troubled by abdominal pain, diarrhoea, bloating, joint pain , fatigue and many other symptoms. He tested negative for coeliac diseases but his health improved dramatically after he switched to a gluten-free diet.

for every person with coeliac disease there may be at least 6 or 7 people with NCGS

Dr Rostami estimated that for every person with coeliac disease there may be at least 6 or 7 people with NCGS. He said NCGS may therefore affect 6 to 10 per cent of the population, between four and seven million people in the UK and the vast majority are unaware that they have a sensitivity to gluten.

Experts have described NCGS as  a combination of IBS-like symptoms (including abdominal bloating and pain, bowel habit abnormalities and other symptoms which affect different parts of the body including a foggy brain, headaches  fatigue, muscle and joint pain, leg or arm numbness, dermatitis , depression and anaemia.

What’s important though is that you carry on eating gluten and get tested for coeliac disease first so that can be eliminated.

What’s important though is that you carry on eating gluten and get tested for coeliac disease first

What about FODMAPs?

Another theory currently fashionable is that it isn’t the gluten in wheat that causes the sensitivity in NCGS patients at all, but other components called FODMAPs ( fermentable oligosaccharides, disaccharides, monosaccharides and polyols) . These are short -chained carbohydrates ( sugars) or sugar alcohols that are found in a wide range of foods and drinks. FODMAPs are poorly absorbed in the small intestine and can enter the colon where they are fermented by bacteria, stretching the bowel and causing bloating, a swollen tummy and diarrhoea.

Foods high in FODMAPs include onions, garlic, beetroot, Savoy cabbage, apples ,pears , mangos and in susceptible individuals, milk and dairy products

Foods high in FODMAPs include onions, garlic, beetroot, Savoy cabbage, apples ,pears , mangos and in susceptible individuals, milk and dairy products, plus diet products containing sorbitol. Bread also contains FODMAPs and if it’s one of  your  dietary staples it  can lead to significant symptoms.


A number of studies have found that a low FODMAPs diet can improve symptoms in 74 per cent of IBS cases – but critics also say a low FODMAPs diet can be difficult to stick to as they’re found in so many foods.

Lactose intolerance – what is it?

Most people who experience bloating and diarrhoea after eating dairy products don’t have a milk allergy, but an intolerance to lactose a sugar found in milk or to some of the proteins in milk. They lack an enzyme called lactase which digests lactose, so lactose is not broken down and passes on through the digestive system, causing wind, bloating and diarrhoea. If you or your family have  moved to the UK from  China, Africa or the Caribbean there’s a strong likelihood that your genetic makeup makes you more likely to be lactose intolerant. Even in northern Europe, the chances of lactose intolerance are as high as one in 10.


If you do notice your symptoms start after eating dairy products ask your GP for a glucose hydrogen breath test. If you test positive – cutting out dairy products should stop your symptoms.

It’s also possible to develop a temporary type of lactose intolerance (called secondary lactose intolerance) after giving up gluten. This is because damaged villi in the gut can mean that production of lactase needed to digest lactase is disrupted. This usually stops after the villi heal – but this can sometimes take months or years.




What’s Up with Your Gut? Jo Waters and Professor Julian Walters is published by Hammersmith Press (£14.99) available on amazon.co.uk

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