What Is Inflammatory Bowel Disease (IBD)?

Inflammatory bowel disease (IBD) is a chronic condition of gut inflammation and includes Crohn's disease and ulcerative colitis (UC). Studies determined that IBD affected 1 in 209 adults in the United States in 2016, and rates have risen over time. It affects 3.1 million Americans. Inflammation in various portions of the gastrointestinal (GI) tract in IBD leads to abdominal pain, diarrhea, rectal bleeding, and/or weight loss symptoms.

This article will discuss the types of IBD, symptoms, causes, and treatment.

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Types of IBD

"Inflammatory bowel disease" is an umbrella term that includes Crohn's disease and ulcerative colitis. Each has different patterns of inflammation.

Crohn's Disease

Crohn's disease is a chronic disease that can affect any part of the GI tract, from the mouth to the small intestine to the colon, rectum, and anus. Most commonly, the small intestine and large intestine are affected. The inflammation in Crohn's disease is usually patchy, with areas of normal tissue between inflamed areas.

The entire thickness of the GI tract wall is affected by the inflammation. Inflammation often comes and goes, resulting in flares that may worsen with time.

Ulcerative Colitis

In contrast to Crohn's, UC tends to affect just the lower portion of the GI tract, including the colon and rectum. Rather than patches of inflammation as in Crohn's, the entire portion of bowel is affected in UC, while inflammation is limited to the innermost layer of the GI tract, causing ulcers.


While their symptoms may be similar, IBD and irritable bowel syndrome (IBS) are completely different disorders of the GI tract. IBS involves the large intestine and causes stool changes (diarrhea or constipation) and abdominal pain. It's much more common than IBD, and thought to affect 1 in 12 adults in the United States.

IBS is often triggered by stress, implicating the role of the gut-brain connection, although the exact cause is not fully understood. Rather than anti-inflammatory or immune-modulating medications, treatment of IBS includes dietary and lifestyle changes, antidiarrheal or constipation medications, and antidepressants.

IBD Symptoms

IBD can cause the following symptoms:

  • Diarrhea- loose stools and increased frequency and/or urgency
  • Abdominal pain and cramping
  • Mucus or blood in the stool
  • Weight loss
  • Tiredness
  • Fever

Sometimes, people with IBD may experience inflammation in other body parts leading to the following symptoms:

  • Joint pain and swelling
  • Skin rash
  • Eye problems
  • Bile duct problems

What Causes IBD?

The exact cause of IBD is unknown, but research points to genetic predisposition. Some mutations involve proteins in the immune system response to bacteria in the GI tract. IBD is also more likely to occur in urban centers of developed countries.

Diagnosing IBD

If your healthcare provider suspects your symptoms may be due to IBD, you will likely be referred to a gastroenterologist, who specializes in diseases of the GI tract. Gastroenterologists can perform a specialized endoscopy, a procedure using a type of scoping mechanism with a camera, to visualize the upper or lower GI tract.

What Is an Endoscopy?

An upper endoscopy (esophagogastroduodenoscopy or EGD) is performed by passing an endoscope through the mouth to visualize the esophagus, stomach, and upper intestine. A lower endoscopy, known as a colonoscopy, is performed by passing an endoscope through the anus to visualize the rectum and colon.

Both tests use sedative medications to keep you calm and comfortable during the procedure. During an endoscopy, biopsies (removing a sample of tissue for analysis in a lab) may be taken for assessment by a pathologist.

Other diagnostic tests for IBD include:

  • Laboratory tests, including inflammatory markers
  • Stool assessment to rule out infection
  • Imaging tests like contrast X-rays, magnetic resonance imaging (MRI), and computed tomography (CT) scans

Can You Reverse IBD?

IBD is not considered reversible, but rather is a chronic and often progressive condition with flares of symptoms that come and go. Some people can go years between flares and be in remission, while others have more frequent symptoms. The goal of treatment is to address symptoms and to prevent flare-ups.

Treatment for IBD

Treatment for IBD includes bowel rest and medications. Surgery to remove affected parts of the intestine or colon may be recommended in severe cases.

Medications for IBD include:

Over the counter medications like antidiarrheal medications, vitamins, and supplements may also be recommended.

What Helps During an IBD Flare-Up?

IBD flare-ups are periods of inflammation and symptoms for which lifestyle factors and medications can help. Severe flare-ups may require bowel rest and a stay at the hospital where intravenous medications can be given. Discuss any flare-up symptoms with your healthcare provider who can create a plan for management.

In the meantime, taking medications as prescribed, getting rest, staying hydrated, and managing stress can help.

Some other tips for managing symptoms include:

  • Taking antidiarrheal medications as recommended by your healthcare provider
  • Keeping the anal area clean, applying barrier ointment, and using sitz baths
  • Taking pain management medications, like acetaminophen (Tylenol), which should be cleared by your healthcare provider

IBD Nutrition and Dietary Tips

The following nutrition tips to help with IBD:

  • Eat a nutritious diet with plenty of fruits, vegetables, and whole grains.
  • Stay well-hydrated.
  • Avoid carbonated drinks.
  • Avoid high-fiber foods like popcorn, nuts, and vegetable skins during flare-ups.
  • Avoid foods high in fat, like fried food and fast food.
  • Discuss any vitamins and supplements with your healthcare provider.

Keeping a record of what you eat can help identify any potentially triggering foods.

Long-Term Complications of IBD

Complications of IBD can be related to IBD itself or to side effects of its treatment. In general, IBD can cause malnutrition, anemia, and osteoporosis due to poor absorption of nutrients.

IBD can directly cause complications, including:

Additionally, problems related to malabsorption can include the following:

Inflammation of the colon in IBD can also increase your risk of colon cancer. Discuss with your healthcare provider whether you should be screened more frequently for colon cancer than is generally recommended.

Living With IBD

IBD can significantly impact daily life, particularly when symptoms are frequent or severe, medication side effects are present, or significant surgeries are required. IBD not only causes significant stress, but it has also been linked to mood disorders, like anxiety and depression. Getting symptoms under control and achieving remission can have a positive impact, as can doing the following:

  • See your healthcare provider regularly for checkups.
  • Take medications as prescribed and avoid missing doses.
  • Get recommended vaccines and screening tests, like colonoscopy.
  • Get regular exercise.
  • Manage stress levels.
  • Discuss any mood symptoms with your healthcare provider.
  • Avoid smoking.


IBD includes chronic inflammatory conditions affecting the GI tract, specifically Crohn's disease and ulcerative colitis. These conditions differ in their location and their pattern of inflammation.

People with IBD experience intermittent flares of symptoms with diarrhea, bloody stool, and weight loss, though other areas of the body may also be affected. Treatment involves anti-inflammatory medications that affect the immune response, and sometimes surgery is required.

13 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Angela Ryan Lee, MD
Angela Ryan Lee, MD, is board-certified in cardiovascular diseases and internal medicine. She is a fellow of the American College of Cardiology and holds board certifications from the American Society of Nuclear Cardiology and the National Board of Echocardiography. She completed undergraduate studies at the University of Virginia with a B.S. in Biology, medical school at Jefferson Medical College, and internal medicine residency and cardiovascular diseases fellowship at the George Washington University Hospital. Her professional interests include preventive cardiology, medical journalism, and health policy.