What Are Irritable Bowel Syndrome Causes?

There are many THEORIES as to Irritable Bowel Syndrome causes and you can learn more about these here.

So, what are the causes of IBS?

Well, the simple answer is we just don’t know what triggers your symptoms.

There have been various theories put forwards, but none of these have been confirmed.

I do believe these theories are valid in the pathogenesis of your IBS, but science has only just scratched the surface.

I will outline some of these for you below. 

Possible Irritable Bowel Syndrome Causes

Could Psychology Play A Role?

Studies have shown up to 50% of sufferers have underlying PSYCHOLOGICAL problems including anxiety, depression and other mental health issues.

What's happening in the mind seems to have a detrimental effect on symptoms which are already present rather than the condition being ‘all in the mind’. 

Have you ever wondered why your symptoms don’t occur at night? Well, this theory may go some way to explaining it.

If you're experiencing night time symptoms, I really would question whether you actually have the condition or not.

In my experience, IBS causes daytime not night time symptoms although there are no absolutes with this. 

Psychiatric drugs such as antidepressants can help symptoms which supports this theory. 

Irritable Bowel Syndrome Causes Picture

Increased Gut Sensitivity

We know that “TRANSIT” of stool is either increased or decreased.

We also know the gut is extra sensitive to the foods you eat, but the reasons behind this are not clear.

The intestine is sensitive to the signals from the brain and this could explain the symptoms you experience.

Stress And Psychological Theory

There is an intimate LINK between IBS and psychology and treatments such as cognitive behavioural therapy and hypnosis help.

How many times have you found your colon upset when you're under stress? A lot I expect.

Psychology definitely has a significant effect on the intestine whether you have IBS or not.

Brain-Gut Theory

As you know, no one knows for sure the cause, but the main recurring issue with all IBS causes is pain and change in bowel habit.

Doctors call this “increased visceral sensitivity”, but what does this really mean? It means your gut is hypersensitive for some reason.

One theory is the the gut being intimately linked with the brain and there is good evidence for this.

The so called BRAIN-GUT AXIS hypothesis works on the theory that your brain is stimulated by smell, sight, touch, hearing and this creates feelings.

We know when you have feelings of stress, regardless of whether your intestine is “normal” or not, you tend to develop abdominal symptoms such as diarrhoea and abdominal pain.

This occurs when the brain processes these senses and then sends messages down the spinal cord to the gut.

In the case of your IBS, there are either abnormal increased signals to the gut, or the gut has increased sensitivity to them, resulting in gut spasms and chronic stomach pain you experience.

This is a TWO WAY theory, as foods which trigger your IBS can equally have an effect on the gut nerves sending signals to the brain.

Also, the neurotransmitter SEROTONIN is in the intestine as well as the brain. In fact, 95% of serotonin is in the intestine compared with 5% in the brain.

So, this is a good theory for IBS which holds some weight in my opinion.

Brain-Gut Theory Picture

Gluten Sensitivity

GLUTEN, a protein in wheat, rye and barley has an effect on the small bowel and can lead to diarrhoea and abdominal pain in those sensitive to it.

People with IBS are often sensitive to gluten and avoid it.

Coeliac disease, a condition affecting the small intestinal lining is damaged by gluten and often mistaken for IBS.

Infective IBS Causes

We know that some people develop IBS after a bout of GASTROENTERITIS, when it is referred to as IBS-PI or post-infectious Irritable Bowel Syndrome.

Theories have been put forward for an infective cause, in view of this.

In a condition known as small intestinal bacterial overgrowth, the intestine is overpopulated by inappropriate bacteria (the so called bad bacteria) and symptoms are similar to IBS.

Probiotics are thought to work by replacing these bacteria with “good bacteria” and some people find their symptoms significantly improve.

Dietary Causes

Irritable Bowel Syndrome causes lots of problems when your DIET isn't quite right.

We all know diet has an effect and, depending on the food, can either improve or trigger symptoms.

This is a big topic and one that I believe is very important in the theory of Irritable Bowel Syndrome causes.

Return To Top of Page