Crohn’s disease can affect any part of the intestines, but it often affects the small intestine, also called the small bowel.

Although Crohn’s disease can affect any part of the intestine, it most often affects the small bowel.

The article below examines Crohn’s disease in the small bowel, its symptoms, diagnosis, treatment, management, and general outlook.

A diagram of Crohn's disease in the small bowelShare on Pinterest
Illustrated by Jason Hoffman

About one-third of people with Crohn’s disease have small bowel involvement only. In about 50% of people with Crohn’s, the disease affects the small bowel and the large intestine, and in about 20% of people, Crohn’s affects the large intestine only.

The three sections of the small bowel include the:

  • ileum
  • jejunum
  • duodenum

According to the Crohn’s and Colitis Foundation, Crohn’s disease in the small bowel most commonly affects the ileum.

Learn more about the types of Crohn’s disease here.

Symptoms

When Crohn’s affects the small bowel, symptoms may include:

In severe cases, deep ulcers may develop in the small intestine. Ongoing inflammation can also lead to the development of scar tissue in the small bowel. This may slow food movement through the bowel and lead to severe cramps.

Learn more about the symptoms of Crohn’s disease here.

Possible tests to diagnose inflammatory bowel disease (IBD) include a colonoscopy. However, doctors do not consider a colonoscopy useful when diagnosing Crohn’s disease in the small bowel. This is because the proximal bowel is not accessible through a colonoscopy.

Additional imaging tests are required to help doctors diagnose Crohn’s disease in the small bowel.

2016 research found doctors may recommend a capsule endoscopy when they suspect Crohn’s disease in the small bowel. This test involves an individual swallowing a small capsule that contains a tiny wireless camera. As the camera travels through the small bowel, it records and transmits images.

Another option includes a CT enterography, a special CT scan that can see the small bowel better.

Learn more about CT scans for Crohn’s disease here.

There is no cure for Crohn’s disease, but treatment is available to manage the condition. Regardless of which section of the intestine or small bowel Crohn’s affects, treatment aims at:

  • reducing inflammation
  • decreasing flare-ups
  • providing adequate nutrition

Learn more about treatments for Crohn’s disease here.

Treatment may include:

Medications

Various classifications of medications may help manage small bowel Crohn’s disease. Medications may include:

Learn about some natural remedies that may help reduce symptoms here.

Surgery

Ongoing inflammation can damage small bowel tissue. If the damage becomes severe enough, medication alone may not help. Doctors may sometimes recommend surgery to treat small bowel Crohn’s disease. For instance, a small bowel resection involves removing damaged tissue at the end of the small bowel.

Learn more about Crohn’s disease surgery here.

There are additional ways to manage Crohn’s disease. Proper management may reduce the severity of symptoms and the frequency of flare-ups.

General guidelines from the American College of Gastroenterology include dietary changes.

During a flare-up, recommendations may include enteral nutrition. This involves delivering liquid nutrients directly to the stomach or small intestine, typically through a tube. External nutrition involves a liquid diet regimen with the needed calories and nutritional requirements.

Some healthcare providers may also recommend the Crohn’s disease exclusion diet. The exclusion diet involves limiting foods that may adversely affect the gut bacteria, cause inflammation, or inhibit nutrient absorption. The diet typically excludes the following:

Individuals with Crohn’s disease in the small bowel may become at risk of nutritional deficiencies. For instance, common symptoms, such as diarrhea, may reduce the absorption of vitamins and minerals.

A nutritionist can help develop an appropriate nutritional plan to meet a person’s needs.

Learn more about nutritional deficiencies and Crohn’s disease here.

The outlook for Crohn’s disease in the small bowel may vary depending on the extent of the bowel affected. Individuals that develop complications may require multiple surgeries.

This 2020 study found that people with untreated inflammatory bowel diseases (IBD), including Crohn’s disease, may have a reduced life expectancy. The study found that although life expectancy has improved for people with IBD, a gap remains.

Learn more about the outlook for people with Crohn’s disease.

Crohn’s disease can affect any portion of the small or large intestines, but the majority of cases involve the small bowel. Symptoms may include diarrhea, stomach cramps, and weight loss. Treatment aims to reduce inflammation and prevent flare-ups.