Our digestive system has an extremely important function. It is how we process the food we eat and extract the nutrients we need to live our active daily lives.

We take in our food through our mouths. Ingested food is then processed and broken down in a series of steps as it passes through the various organs of our digestive system or gut: from the mouth through the oesophagus down into the stomach, then through the intestines and into the bowel where it is prepared for excretion out of the body at the anus.

Food passes through our gut and is metabolised, in other words, turned into a form that the body can absorb. We absorb the nutrients we require and they pass through into the bloodstream and are taken around the body to where they are needed.

In inflammatory bowel disease (IBD) our digestive system is impaired and the gut becomes inflamed and swollen.

There are two very similar forms of inflammatory bowel disease: Crohn’s disease and ulcerative colitis.

The two types of IBD can be hard to tell apart. In both diseases, there is inflammation and damage to the intestine wall in the form of lesions or sores that often bleed easily.

In Crohn’s disease, symptoms can be more severe and any part of the intestine can be injured, but problems are most common in the small intestine or ileum near the entrance to the large intestine.

The disease lesions are concentrated in patches and penetrate deeper layers of the intestinal wall.  The lesions are often called skip lesions, as there can be areas of diseased tissue that are separated by healthy tissue.

Ulcerative colitis is generally a milder condition and affects one specific area of the digestive tract, which is the colon or small bowel.

Disease lesions are more superficial. They are usually restricted to the top layer of the intestinal wall. They are diffuse with uniform inflammation and no areas of healthy tissue in between.

Indeterminate colitis is diagnosed when Crohn’s and ulcerative colitis symptoms overlap and are indistinguishable. It is thought that this can happen in about one in 10 cases.