Why do I have IBD?

Unfortunately there isn’t a simple answer as to why you have an inflammatory bowel disease like Crohn's disease, ulcerative colitis or IBDU.

Doctors and scientists are still trying to work out the exact causes of why someone has IBD, but what we do know is that it isn’t your fault. 

At the moment it’s thought IBD may be caused by a combination of different things. This means it’s probably a combination of a few or all these things together could cause it.

Your genes

Genes are passed from a mother and father to their baby and help to decide which of its parents the baby looks like, the colour of its hair, eyes etc. Genes can also pass illnesses and diseases from parents to a child. 

Some of the genes you inherited from your parents may have made it more likely you would get IBD.

But, having some of these genes doesn’t mean you will definitely have IBD - which is why your mother, father or brothers/sisters may not have IBD but you do. 

Lots of genes are shared among families and you may find other members of your wider family - such as aunts/uncles, cousins or grandparents - have an inflammatory bowel disease.

Our environment

It’s thought that things in the environment around us could increase our chances of getting IBD. This may include things that enter our body - such as the food we eat, bacteria and the air we breathe, but also things like stress and getting less sleep.

Years and years ago we didn’t have the amount of pollution we have now, we would eat more fruit and vegetables (and fast food didn’t exist), we got more sleep and were less stressed at school. All of these things (and many, many more) may be placing a strain on our body that it doesn't know how to cope with and this could be causing it not to work in the way it needs to.

A reaction by your immune system

In inflammatory bowel disease your immune system is attacking your digestive system. But, we don’t really know why this starts happening.

Some doctors think IBD happens when the immune system starts working harder to protect your body from an illness or infection, but doesn’t stop working as hard when the illness has gone. Other doctors think it might just be because your immune system malfunctions (goes a bit wrong).

Bacterial composition of the bowel

Your digestive system is full of lots of bacteria which help your body to work. More and more research is being carried out into this bacteria and we now know that the bacteria of people with IBD tends to be different to people who don’t have IBD.

However, we don’t know if this change in bacteria is what causes IBD, or if your IBD causes a change in the bacteria (known as cause and effect).

There’s lots of research going on to work out more about why people get IBD, but we may never know exactly why.