What is ileocolitis?

Ileocolitis is the most common type of Crohn’s disease. It causes inflammation in the end of the small intestine (known as the ileum) and the colon (large intestine).


Ileocolitis is the most common type of Crohn’s disease. It causes inflammation in the end of the small intestine (known as the ileum) and the colon (large intestine) - most often on the right side.

Around 50% of people with Crohn’s disease are diagnosed with ileocolitis. It is a life-long chronic condition which cannot currently be cured and is part of a group of conditions known as inflammatory bowel disease (IBD).

What is Crohn's disease?

Crohn’s disease causes inflammation in the gastrointestinal (GI) tract. It most commonly affects the small intestine and the beginning of the large intestine, however it can affect any part of the GI tract from the mouth to the anus.

Crohn’s disease affects the entire thickness of the digestive tract wall and may also skip areas - meaning you could have inflammation near you mouth and also in your small bowel but no where in between.

It is common for people with Crohn’s disease to be diagnosed with more than one type of the condition if inflammation is present in several places in the GI tract.

What are the symptoms of ileocolitis?

Typical symptoms include:

  • Diarrhoea
  • Cramping or pain in the right lower part or middle of the abdomen
  • Significant weight loss
  • Fatigue

What are the treatments for ileocolitis?

Treatments currently include medication and surgery. Some people have severely inflamed or damaged parts of their bowels surgically removed. This can reduce or eliminate the symptoms, however it does not get rid of the disease and there is a risk that it will return to another area of the GI tract in the future.

Some people also make adjustments to their diet and lifestyle to support their medical treatment - such as exercise, improving quality of sleep, reducing stress.

What complications can occur with ileocolitis?

  • Fistulas: Fistulas or inflammatory abscesses may form in the right lower part of the abdomen. A fistula is a channel that develops between one organ and another so that they are connected. There are many different types of fistulas (depending on where the fistula links between). Around 1 in 3 people with Crohn’s disease develop a fistula at some point
  • Strictures: Over time the wall of the colon can become thickened due to scar tissue caused by chronic inflammation. This can cause the intestine to become blocked, either partially or fully, slowing or stopping movement of food or stool through the intestines. A complete bowel obstruction is life-threatening and often requires surgery
  • Malnutrition: Due to a lack of appetite malnutrition can occur in those with gastroduodenal Crohn’s disease. Nutritional deficiencies can also occur
  • Colon cancer: There may be an increased risk of developing cancer
  • Abscesses: This is where a pocket of pus caused by infection from bacteria can form in the intestinal wall, sometimes causing it to bulge out
  • Bile acid malabsorption (BAM): Damage to the ileum or surgery to it can cause BAM. The main symptom is diarrhoea

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