What is IBS and what causes it?

Irritable Bowel Syndrome (IBS) is often dismissed as unimportant, but the symptoms, which include abdominal pain, bloating, gas, constipation and/or diarrhoea, as well as fatigue, depression and anxiety, can make people truly miserable and have a huge impact on quality of life.

A collection of symptoms rather than a specific disease process or certain ‘illness’, IBS is generally diagnosed when doctors have ruled out other pathologies such as a gastric infection, IBD (Crohn’s or Ulcerative Colitis), celiac disease and cancer. But the vague nature of the syndrome and lack of a simple solution means that patients are often left with little relief.

There are various different reasons why someone might be experiencing IBS. Finding the root cause or causes (it’s likely to be multi-factorial) of the individuals’ symptoms is the first step to rebalancing health.

So what’s going on? Here are some of the things at play.

Gastric juices

After chewing and swallowing food several gastric juices are needed to aid the digestion of food. If these (stomach acid, pancreatic enzymes and bile) are impaired you’ll be unable to properly break down foods, absorb them and eliminate them. Poorly digested foods lead to fermentation in the gut, imbalances in gut microbiome, food intolerances and lack of absorption of nutrients.

Reasons for low gastric juices include the use of antacid medication (PPIs), poor chewing, age (they become less potent as we age), infection with bacteria, such as Helicobactor pylori and alpha-glucosidase inhibitor drugs used for treating obesity and type 2 diabetes. But there are lots of things we can do to promote better gastric juice function from the use of bitters and bitter greens to digestive enzymes and a low bile acid diet.

Gastric infection

Studies have shown that in a significant number of cases, IBS comes after a bacterial or parasitic infection such as food poisoning or travellers diarrhea. It may well be the case that the infection is completely resolved, in fact it may have been resolved for some time, but the disruption to the microbiome and increased and unresolved inflammation in the gut triggers and drives IBS.

Alterations in the microbiome

The good bacteria which live in our guts do a whole load of things to protect and promote our health, much of which we are just discovering. Their role in healthy digestion and immune function (inflammation regulation) is key. Dysregulation or ‘dysbiosis’ can lead to all kinds of symptoms including, constipation, diarrhoea, cramping and bloating as well as fatigue, dysregulated immunity, brain fog, fatigue and mood changes.

There are various ways in which the gut microbiome can become disrupted, antibiotic use, weak gastric juices, bacterial infection, candida, poor diet and stress being amongst them. Addressing and rebalancing gut microbiome can be fundamental to finding relief in IBS.

Chronic stress

When you are stressed or feel threatened the body switches into a ‘sympathetic’ state and gets you ready for fight or flight. It prepares for attack. It switches on the immune system, releases glucose into the bloodstream (incase you have to run), increases your heart beat and dilates your pupils.

At the same time it de-prioritises digestion by inhibiting secretion of gastric juices and motor activity through the digestive tract. This leads to abdominal cramping, poor nutrient absorption and diarrhoea or constipation. Conversely the ‘parasympathetic state’ or ‘rest and digest’ promotes good digestive function. Unfortunately, many of us live in a stressed state for much of the day, and our body hasn’t adapted to understand that it isn’t actually in terrible physical danger so, in many cases we need to make a concerted effort to haul it back over to ‘rest and digest’. Yoga, meditation and mindfulness can have a really beneficial impact here.

Food intolerances

A lot of people with IBS see an improvement when they remove certain foods from their diet. Common offenders are gluten and dairy but other common problem foods include wheat, coffee, alcohol, eggs, onions, citrus foods and yeast.

If you feel you have a food intolerance consider trying an elimination diet which involves removing suspect foods for about 4 weeks and the slowly reintroducing them one at a time, this may be easier to do with the guidance of a professional. Another option is food intolerance (immunoglobulin G) testing. Food intolerance tests have come under some criticism because of their lack of accuracy but they might be a good place to start to uncover which foods are effecting you.

Intestinal permeability

Your digestive tract is essentially one long tube from your mouth to your back end, the lining of which is just one cell thick, imagine it! Intestinal permeability, or ‘leaky gut’, occurs when the tight junctions between the cells becomes compromised and particles (beyond the usual nutrients) are able to ‘leak’ through into the blood stream.

This can result in inflammation in the gut lining and potentially throughout the body. Intestinal permeability is induced through poor diet, over the counter pain killers, alcohol, stress and anything which disrupts the microbiome.

Changes in gut-brain interactions

We’ve all experienced ‘butterflies’ or had a knot in our stomach when we’ve felt anxious, this is because the brain and the gut are in constant communication via our neurotransmitters, the vagus nerve and hormones. It makes perfect sense then that what is going on in our brain is effecting our gut and vice versa. Many people who suffer from IBS also suffer from depression and anxiety.

This bi-directional relationship is fascinating and brings completely new meaning to the idea that ‘it’s all in your head’. We now know that changes in microbiome in the gut can lead to symptoms of anxiety and depression, so maybe ‘it’s all in your gut’.

Working with a nutritional therapist to get to the bottom of what’s going on on an individual basis can be the starting point to rebalancing the gut and a longterm resolution.