Crohn’s disease can involve any part of your intestinal tract. Inflammation from Crohn’s disease commonly causes abdominal pain and diarrhea. This inflammation can affect all layers of tissue in the lining of the intestine and can lead to a variety of complications.

Here are some of the most likely complications:

Intestinal blockage

This is the most common complication of Crohn’s disease. Swelling and scarring can narrow the passage through your intestines, causing a bowel obstruction. This can cause nausea, vomiting, bloating, constipation, and abdominal pain.


Chronic inflammation of the lining of the intestine can cause internal sores called ulcers to develop. Ulcers may occur anywhere in your digestive tract, including your mouth and anus. They can also occur in the genital area.


Ulcers can penetrate deeply into the tissue of the intestinal wall. They may even form a tunnel all the way through the wall of the intestine. This is called a fistula.

Fistulas create abnormal connections between different parts of your intestine, your intestine and your skin, or your intestine and other structures, such as the bladder, the vagina, or the aorta.

There are five types of fistulas:

  • Aortoenteric fistula: This occurs when a tract is formed between the bowel and the aorta. It’s a serious and potentially life-threatening condition, since massive amounts of blood can be lost in a short period of time.
  • Entero-vesical fistula: A fistula between the intestine and the bladder is called an entero-vesical fistula. This can cause frequent urinary tract infections. It may also cause you to pass gas and feces during urination.
  • Entero-cutaneous fistula: A fistula between the intestine and the skin is called an entero-cutaneous fistula. This can cause an opening on the skin of the abdomen. Pus, bowel contents, and mucus may discharge from this opening.
  • Colo-vaginal fistula: A fistula between the colon and the vagina is called a colo-vaginal fistula. This can cause gas and feces to pass through the vagina.
  • Anal fistula: A fistula from the anus to the skin is called an anal fistula. Mucus, pus, and stool may discharge from the anus through the fistula to the skin.

Another related complication is an abdominal abscess. This occurs when a hole or perforation occurs in the intestine and drains intestinal contents directly into the abdominal cavity. Severe pain and infection will soon set in. This is a serious condition that can result in sepsis and death.


Malabsorption is common with Crohn’s disease. It can lead to nutritional deficiencies, as scarred and damaged tissues fail to absorb nutrients properly. If you have chronic diarrhea, your intestines may not have time to absorb nutrients. Malabsorption can also lead to anemia and malnutrition.


Osteoporosis is a weakening of the bones caused by a loss of calcium. This is especially common if your treatment plan has included corticosteroids.

Increased risk of cancer

Crohn’s disease increases your risk of developing colon cancer. Regular screenings are recommended.

Complications in children

Children with Crohn’s disease may have impaired growth and delayed sexual development due to malnutrition and vitamin or mineral deficiencies.

Other common complications

Other complications of Crohn’s disease include:

Long-term outlook

Most people with Crohn’s disease experience periods of remission and flare-up. Up to 75 percent of patients will eventually require surgery, and some people will require multiple surgeries.

Crohn’s disease is a life-altering condition. While some people with Crohn’s disease may have very few symptoms with proper medical treatment, many others will continue to struggle with medical complications and pain.

If you’re diagnosed with Crohn’s disease, it’s important to find a gastroenterologist with whom you are comfortable and can develop a good working relationship so that your treatment plan can be tailored to your needs. Some people with Crohn’s disease also benefit from becoming involved in support groups with others who have been diagnosed with Crohn’s disease.