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Inflammatory bowel disease (IBD) represents a group of intestinal disorders that cause prolonged inflammation of the digestive tract.

The digestive tract comprises the:

  • mouth
  • esophagus
  • stomach
  • small intestine
  • large intestine

It’s responsible for breaking down food, extracting the nutrients, and removing any unusable material and waste products.

Inflammation anywhere along the digestive tract interferes with this normal process. IBD can be very painful and disruptive. In rare cases, it may even be life threatening.

Learn all about IBD, including the different types, what causes it, and its complications.

The Crohn’s & Colitis Foundation of America (CCFA) estimates that around 1.6 million people in the United States have IBD.

Many diseases are included under the umbrella term IBD. The two most common ones are ulcerative colitis (UC) and Crohn’s disease.

UC involves inflammation of the large intestine.

Crohn’s disease can cause inflammation in any part of the digestive tract. However, it mostly affects the tail end of the small intestine.

The exact cause of IBD is unknown.

However, the biggest risk factors for developing UC and Crohn’s disease include:

Family history and genetics

People who have a parent, sibling, or child with IBD are at a much higher risk for developing it themselves. This is why scientists believe IBD may have a genetic component.

The immune system

The immune system may also play a role in IBD.

The immune system normally defends the body from pathogens, which are organisms that cause diseases and infections.

A bacterial or viral infection of the digestive tract can trigger an immune response. The digestive tract becomes inflamed as the body tries to create an immune response against the invaders.

In a healthy immune response, the inflammation goes away when the infection is gone.

In people with IBD, however, digestive tract inflammation can occur even when there’s no infection. The immune system attacks the body’s own cells instead. This is known as an autoimmune response.

IBD can also occur when the inflammation doesn’t go away after the infection is cured. The inflammation may continue for months or even years.


Smoking is one of the main risk factors for developing Crohn’s disease. Smoking also aggravates the pain and other symptoms associated with Crohn’s disease. It increases the risk of complications too.

However, UC primarily affects nonsmokers and ex-smokers.


IBD is present in all populations. However, according to research, certain ethnic groups, including white people and Ashkenazi Jews, have a higher risk for developing the condition.

IBD rates are also rising among Black people in the United Kingdom, according to a 2011 study conducted by Crohn’s and Colitis UK.


IBD can happen at any age, but in most cases, it starts before the age of 35 years old.

Environmental factors

People who live in urban areas and industrialized countries have a higher risk for developing IBD, according to research. Residents of industrialized countries tend to eat more fat and processed food.

IBD is also more common among people living in northern climates, where it’s often cold.

Researchers reviewing the impact of environmental factors on IBD have found that having a sedentary lifestyle or job increases your risk for IBD too.

On the other hand, some studies, including a 2013 study, have shown that physical activity in the pre-illness period helped to reduce the risk of the onset of IBD. This reduction was found to be stronger for Crohn’s disease than UC.


IBD tends to affect men and women equally.

According to a 2018 study, UC is generally more common among men over 45 years old than it is among women of the same age range.

On the other hand, Crohn’s disease is more common among girls and women over age 14 years.

Symptoms of IBD vary depending on the location and severity of inflammation, but they may include:

People with Crohn’s disease may also get canker sores in their mouths. Sometimes ulcers and fissures also appear around the genital area or anus.

IBD can also be associated with problems outside of the digestive system, such as:

Possible complications of IBD include:

  • malnutrition with resulting weight loss
  • colorectal cancer
  • fistulas, or tunnels that go through the bowel wall, creating a hole between different parts of the digestive tract
  • intestinal rupture, which is also known as perforation
  • bowel obstruction

In rare cases, a severe bout of IBD can make you go into shock. This can be life threatening. Shock is usually caused by blood loss during a long, sudden episode of bloody diarrhea.

To diagnose IBD, your doctor will first ask you questions about your family’s medical history and your bowel movements.

A physical exam may then be followed by one or more diagnostic tests.

Stool sample and blood test

Stool samples and blood tests can be used to look for infections and other diseases.

Blood tests can also sometimes be used to distinguish between UC and Crohn’s disease. However, blood tests alone can’t be used to diagnose IBD.

Barium enema

A barium enema is an X-ray exam of the colon and small intestine. In the past, this type of test was often used, but now, other tests have largely replaced it.

Flexible sigmoidoscopy and colonoscopy

These procedures use a camera on the end of a thin, flexible probe to look at the colon.

The camera is inserted through the anus. It allows your doctor to look for ulcers, fistulas, and other damage or abnormalities in the rectum and colon.

A colonoscopy can examine the entire length of the large intestine. A sigmoidoscopy examines only the last 20 inches of the large intestine — the sigmoid colon.

During these procedures, a small sample of the tissue inside the intestine will sometimes be taken. This is called a biopsy. This sample can be examined under a microscope and used to diagnose IBD.

Capsule endoscopy

This test inspects the small intestine, which is much harder to examine than the large intestine. For the test, you swallow a small capsule containing a camera.

The camera takes pictures as it moves through your small intestine. Once you’ve passed the camera in your stool, the pictures can be seen on a computer.

This test is only used when other tests have failed to find the cause of Crohn’s disease symptoms.

Plain film or X-ray

A plain abdominal X-ray is used in emergency situations where intestinal rupture is suspected.

CT and MRI scans

CT scans are basically computerized X-rays. They create a more detailed image than a standard X-ray. This makes them useful for examining the small intestine. They can also detect complications of IBD.

MRIs use magnetic fields to form images of the body. Since they don’t require radiation, they’re safer than X-rays. MRIs are especially helpful in examining soft tissues and detecting fistulas.

Both CT scans and MRIs can be used to determine how much of the intestine is affected by IBD.

There are a number of different treatments for IBD.


Anti-inflammatory drugs are the first step in IBD treatment. These drugs help decrease inflammation of the digestive tract. However, they have many side effects.


Glucocorticoids, a subcategory of corticosteroids, are examples of anti-inflammatory drugs used for IBD. They include:

  • budesonide (Uceris)
  • prednisone (Prednisone Intensol, Rayos)
  • prednisolone (Millipred, Prelone)
  • methylprednisolone (Medrol, Depo-Medrol)

These drugs are available in a variety of forms, from oral tablets to injections to rectal foams. They’re usually given at the lowest dose possible for the shortest amounts of time.

5-ASA drugs (aminosalicylates)

5-ASA drugs (aminosalicylates) also decrease inflammation, mainly in the last part of the small intestine and in the colon. They include:

  • balsalazide (Colazal)
  • mesalamine (Apriso, Asacol HD, Canasa, Pentasa)
  • olsalazine (Dipentum), which is only available as a brand-name drug
  • sulfasalazine (Azulfidine)

In 2019, the American Gastroenterological Association (AGA) released treatment guidelines for adults with extensive mild to moderate UC. For this group, they strongly recommended:

  • standard-dose oral mesalamine
  • diazo-bonded 5-ASA drugs, such as balsalazide and olsalazine

They’re preferred over low-dose mesalamine, sulfasalazine, or no treatment. However, the AGA also says it’s fine to take sulfasalazine, as long as you’re aware that it comes with greater side effects.

People who don’t respond to standard-dose mesalamine or diazo-bonded 5-ASA drugs should try a combination of rectal mesalamine and high-dose oral mesalamine.


Immunomodulators may be an option if corticosteroids and 5-ASA drugs aren’t enough. They prevent the immune system from attacking the bowel and causing inflammation.

They include:

The Food and Drug Administration (FDA) hasn’t approved these drugs for the treatment of IBD. However, your doctor may prescribe them anyway. This is referred to as off-label drug use.


Off-label drug use is when a drug that’s approved by the Food and Drug Administration (FDA) for one purpose is used for a different purpose that hasn’t yet been approved.

However, a doctor can still use the drug for that purpose. This is because the FDA regulates the testing and approval of drugs, but not how doctors use drugs to treat medical conditions in their patients.

So your doctor can prescribe a drug however they think is best for your care.


Biologics are genetically designed drugs that may be a choice for people with moderate to severe IBD.

Some biologics block tumor necrosis factor (TNF). TNF is a chemical that causes inflammation and is produced by the immune system. Excess TNF in the blood is normally blocked, but in people with IBD, higher levels of TNF can lead to more inflammation.

TNF-alpha inhibitors include:

Other biologics include:

Biologics aren’t available as generic drugs. Biosimilars, which are cheaper and have been reverse-engineered to produce the same results as biologics, are available for some of these drugs, though.

In 2020, the AGA released treatment guidelines for people with moderate to severe UC. They recommended that people who’ve never tried a biologic before opt for infliximab or vedolizumab over adalimumab. Adalimumab is less effective.

Adalimumab can be self-administered, which may make it more convenient than the other drugs. If convenience is a concern, it’s fine to choose adalimumab instead.

Other drugs

Other drugs block separate pathways causing inflammation, including the UC drug tofacitinib (Xeljanz). Due to safety concerns, the AGA recommends that this oral drug only be taken during a clinical or registry study.

Antibiotics are used to kill bacteria in the small intestine that may trigger or aggravate the symptoms of Crohn’s.

Antidiarrheal medications and laxatives can also be used to treat IBD symptoms.

Shop for antidiarrheal medications and laxatives online.

Lifestyle choices

Lifestyle choices are important when you have IBD.

Drinking plenty of fluids helps to compensate for those lost in your stool. Avoiding dairy products and stressful situations also improves symptoms.

Exercising and quitting smoking, if you smoke, can further help improve your health.


Vitamin and mineral supplements can help with nutritional deficiencies. For example, iron supplements can help treat anemia.

Talk with your doctor before adding any new supplements to your diet.

Shop for iron supplements online.


Surgery can sometimes be necessary for people with IBD. Some IBD surgeries include:

Routine colonoscopy is used to monitor for colorectal cancer, since those with IBD are at a higher risk for developing it.

The hereditary causes of IBD can’t be prevented. However, you may be able to reduce your risk for developing IBD or prevent a relapse by:

IBD can cause some discomfort, but there are ways you can manage the disease and still live a healthy, active lifestyle.

Visit the Crohn’s & Colitis Foundation for resources and more information on IBD, including UC and Crohn’s disease.

It can also be helpful to talk with others who understand what you’re going through.

IBD Healthline is a free app that connects you with others living with IBD through one-on-one messaging and live group chats while also providing access to expert-approved information on managing IBD.

Download the app for iPhone or Android.

Read this article in Spanish.