The term inflammatory bowel disease (IBD) describes a group of disorders in which the intestines become inflamed. It has often been thought of as an autoimmune disease, but research suggests that the chronic inflammation may not be due to the immune system attacking the body itself. Instead, it is a result of the immune system attacking a harmless virus, bacteria, or food in the gut, causing inflammation that leads to bowel injury.
Two major types of IBD are ulcerative colitis and Crohn's disease. Ulcerative colitis is limited to the colon or large intestine. Crohn's disease, on the other hand, can involve any part of the gastrointestinal tract from the mouth to the anus. Most commonly, though, it affects the last part of the small intestine or the colon or both.
If you have an IBD, you know it usually runs a waxing and waning course. When there is severe inflammation, the disease is considered active and the person experiences a flare-up of symptoms. When there is less or no inflammation, the person usually is without symptoms and the disease is said to be in remission.
What Causes Inflammatory Bowel Disease?
IBD is a disease with an unknown cause. Some agent or a combination of agents -- bacteria, viruses, antigens -- triggers the body's immune system to produce an inflammatory reaction in the intestinal tract. Recent studies show some combination of hereditary, genetic, and/or environmental factors may cause the development of IBD. It could also be that the body's own tissue causes an autoimmune response. Whatever causes it, the reaction continues without control and damages the intestinal wall, leading to diarrhea and abdominal pain.
Evidence to suggest a genetic basis for IBD is strong, including:
- Family history: As many as 20% of people with IBD have a family history of it.
- Race and ethnicity: IBD is more common in white people. It's also more common in Jews, especially Ashkenazi Jews.
In 2006, the first gene associated with Crohn's disease, the NOD2 gene, was identified. Since then, researchers have uncovered more than 200 related genomic regions for IBD.
Finding a genetic link would help scientists understand the changes that lead to IBD and help them improve treatments. A genetic link could also lead to a test for IBD.
What Are the Symptoms of Inflammatory Bowel Disease?
As with other chronic diseases, a person with IBD will generally go through periods in which the disease flares up and causes symptoms, followed by periods in which symptoms decrease or disappear and good health returns. Symptoms range from mild to severe and generally depend upon what part of the intestinal tract is involved. They include:
Are There Complications Associated With IBD?
IBD can lead to several serious complications in the intestines, including:
- Profuse intestinal bleeding from the ulcers
- Perforation, or rupture of the bowel
- Narrowing -- called a stricture -- and obstruction of the bowel; found in Crohn's
- Fistulae (abnormal passages) and perianal disease, disease in the tissue around the anus. These conditions are more common in Crohn's than in ulcerative colitis.
- Toxic megacolon, which is an extreme dilation of the colon that is life-threatening. This is associated more with ulcerative colitis than Crohn's.
IBD, particularly ulcerative colitis, also increases the risk of colon cancer.
IBD can also affect other organs. For example, someone with IBD may have arthritis, skin conditions, inflammation of the eye, liver and kidney disorders, or bone loss. Of all the complications outside the intestines, arthritis is the most common. Joint, eye, and skin complications often happen together.
How Is IBD Diagnosed?
Your doctor makes the diagnosis of inflammatory bowel disease based on your symptoms and various exams and tests:
- Stool exam. You'll be asked for a stool sample that will be sent to a laboratory to rule out the possibility of bacterial, viral, or parasitic causes of diarrhea. In addition, the stool will be examined for traces of blood that cannot be seen with the naked eye.
- Complete blood count. A nurse or lab technician will draw blood, which will then be tested in the lab. An increase in the white blood cell count suggests the presence of inflammation. And if you have severe bleeding, the red blood cell count and hemoglobin level may decrease.
- Other blood tests. Electrolytes (sodium, potassium), protein, and markers of inflammation, such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), may be drawn to look at how serious the disease is. Perinuclear antineutrophil cytoplasmic antibody (pANCA) levels may be up in ulcerative colitis. In addition, specific tests for sexually transmitted diseases may be done.
- Barium X-ray. Although seldom used, it can check the upper gastrointestinal (GI) tract -- the esophagus, stomach, and small intestine -- for abnormalities caused by Crohn's disease. You swallow a chalky white solution that coats the intestinal tract so it will be visible on X-rays. If a barium study is used to check the lower GI tract, you will be given an enema containing barium and asked to hold it in while X-rays are taken of the rectum and colon. Abnormalities caused by either Crohn's or ulcerative colitis may show up in these X-rays.
- Other radiologic tests. Computed tomography (CT scan), magnetic resonance imaging (MRI), and ultrasound have also been used in the diagnosis of Crohn's disease and ulcerative colitis.
- Sigmoidoscopy. In this procedure, a doctor uses a sigmoidoscope, a narrow, flexible tube with a camera and light, to visually examine the last one-third of your large intestine, which includes the rectum and the sigmoid colon. The sigmoidoscope is inserted through the anus and the intestinal wall is visually examined for ulcers, inflammation, and bleeding. The doctor may also take samples, called biopsies, of the intestinal lining with an instrument inserted through the tube. These will then be examined in a laboratory under a microscope.
- Colonoscopy. A colonoscopy is similar to a sigmoidoscopy, except that the doctor will use a colonoscope, a longer flexible tube, to examine the entire colon. This procedure gives you a look at the extent of disease in the colon.
- Upper endoscopy. If you have upper GI symptoms such as nausea and vomiting, a doctor will use an endoscope, a narrow, flexible tube with a camera and light, that will be inserted through the mouth -- to examine your esophagus, stomach, and duodenum, which is the first part of your small intestine. Ulceration occurs in the stomach and duodenum in up to one out of every 10 people with Crohn's disease.
- Capsule endoscopy. This test may be helpful to diagnose disease in the small intestine, such as in Crohn's disease. You swallow a small capsule that has a camera in it. Pictures are taken of the esophagus, stomach and small bowel and then sent to a receiver you wear on a belt. At the end of the procedure, the pictures are downloaded from the receiver onto a computer. The camera is passed through your body into the toilet.
What Do You Need to Know About IBD?
When your doctor tells you that you have inflammatory bowel disease, you'll want to get as much information as possible. Be prepared with questions, such as:
- Could any condition other than IBD be causing my symptoms?
- Do I have ulcerative colitis or Crohn's disease?
- What parts of my digestive system has it affected?
- What treatments do you recommend?
- How soon should I expect relief?
- What side effects from the medicines should I watch out for? What should I do if I notice them?
- What should I do if my symptoms return? Are any considered an emergency?
- Are there symptoms outside the digestive system that could be caused by IBD?
- Should I change my diet or take nutritional supplements?
- Would it help me to make any other lifestyle changes?
- When should I have a follow-up appointment, and should I see a specialist?
- What is the long-term outlook for my IBD?
- How often do I need to get a colonoscopy?
How Is Inflammatory Bowel Disease Treated?
Treatment for IBD involves a combination of self-care and medical treatment.
Although no specific diet has been shown to prevent or treat IBD, dietary changes may be helpful in managing your symptoms. It's important to talk with your doctor about ways to modify your diet while making sure you get the nutrients you need. For instance, depending on your symptoms, the doctor may suggest that you reduce the amount of fiber or dairy products that you consume. Also, small, frequent meals may be better tolerated. In general, there is no need to avoid certain foods unless they cause or worsen your symptoms.
One dietary intervention your doctor may recommend is a low-residue diet, a very restricted diet that reduces the amount of fiber and other undigested material that pass through your colon. Doing so can help relieve symptoms of diarrhea and abdominal pain. If you do go on a low-residue diet, be sure you understand how long you should stay on the diet because a low-residue diet doesn't provide all the nutrients you need. Your doctor may recommend that you take vitamin supplements.
Another important aspect of self-care is to learn how to manage stress, which may worsen your symptoms. One thing you might want to do is to make a list of things that cause you stress and then consider which ones you can eliminate from your daily routine. Also, when you feel stress coming on, it can help to take several deep breaths and release them slowly. Learning to meditate, creating time for yourself, and regular exercise are all important tools for reducing the amount of stress in your life.
Participating in a support group puts you in contact with others who know exactly the effect IBD has on your day-to-day life because they are going through the same things you are. They can offer support and tips on how to deal with symptoms and the effect they have on you.
The goal of medical treatment is to stop the abnormal inflammation so intestinal tissue has a chance to heal. As it does, the symptoms of diarrhea and abdominal pain should be relieved. Once the symptoms are under control, medical treatment will focus on decreasing the frequency of flare-ups and maintaining remission.
Doctors often take a step-by-step approach to the use of medications for inflammatory bowel disease. This way, the least harmful drugs or drugs that are only taken for a short period of time are used first. If they don't work, drugs from a higher step are used.
Treatment typically begins with aminosalicylates, which are aspirin-like anti-inflammatory drugs such as balsalazide (Colazal), mesalamine (Asacol, Apriso, Lialda, Pentasa), olsalazine (Dipentum), and sulfasalazine (Azulfidine). Mesalamine can be taken orally or be administered as a rectal suppository or enema to treat ulcerative colitis. Because they are anti-inflammatory, they are effective in both relieving symptoms of a flare-up and maintaining remission. The doctor may also prescribe anti-diarrheal agents, antispasmodics, and acid suppressants for symptom relief. You should not take anti-diarrheal agents without a doctor's advice.
If you have Crohn's disease, especially if it's accompanied by a complication such as perianal disease (diseased tissue around the anus), the doctor may prescribe an antibiotic to be taken with your other medicines. Antibiotics are less commonly used for ulcerative colitis.
If the first drugs don't provide adequate relief, the doctor will likely prescribe a corticosteroid, which is a rapid-acting anti-inflammatory. Corticosteroids tend to provide rapid relief of symptoms along with a big decrease in inflammation. But because of side effects associated with their long-term use, corticosteroids are used only to treat flare-ups and are not used for maintaining remission.
Immune modifying agents are the next drugs to be used if corticosteroids fail or are required for prolonged periods. These medications are not used in acute flare-ups, because they may take as long as 2 to 3 months to work. These medications target the immune system, which releases the inflammation-inducing chemicals in the intestine walls. Examples of the most common immunosuppressives are azathioprine (Imuran), methotrexate (Rheumatrex), and 6-mercaptopurine, or 6-MP (Purinethol).
Biologic therapies are antibodies that target the action of certain other proteins that cause inflammation. Infliximab (Remicade), infliximab-abda (Renflexis), infliximab-axxq (Avsola), and infliximab-dyyb (Inflectra), are drugs approved by the FDA to treat moderate to severe Crohn's disease when standard medications have been ineffective. They belong to a class of drugs known as anti-TNF agents. TNF (tumor necrosis factor) is produced by white blood cells and is believed to be responsible for promoting the tissue damage that occurs with Crohn's disease. Other anti-TNF agents approved for Crohn's disease are adalimumab (Humira), adalimumab-atto (Amjevita), and certolizumab (Cimzia). An alternative to anti-TNF treatment for Crohn's disease are biologics that target integrin, including natalizumab (Tysabri), risankizumab-rzaa(Skyrizi), ustekinumab (Stelara), and vedolizumab (Entyvio).
Adalimumab (Humira), adalimumab-atto (Amjevita), certolizumab (Cimzia), golimumab (Simponi, Simponi Aria), infliximab(Remicade), infliximab-abda (Renflexis), infliximab-axxq (Avsola), and Infliximab-dyyb (Inflectra) are some of the anti-TNF drugs approved by the FDA for ulcerative colitis. Other biologics include ustekinumab (Stelara), and vedolizumab (Entyvio). In addition, small molecule medicines that work on the immune system are available for people with ulcerative colitis. They include tofacitinib (Xeljanz), upadacitinib (Rinvoq), and ozanimod (Zeposia)
If you are not responding to the drugs recommended for IBD, talk with your doctor about enrolling in a clinical trial. Clinical trials are the way new treatments for a disease are tested to see how effective they are and how patients respond to them. You can find out about clinical trials at the Crohn's & Colitis Foundation of America website.
Is Surgery Ever Used To Treat Inflammatory Bowel Disease?
Surgical treatment for IBD depends upon the disease. Ulcerative colitis, for instance, can be cured with surgery, because the disease is limited to the colon. Once the colon is removed, the disease doesn't come back. However, surgery will not cure Crohn's disease, although some surgeries may be used. Excessive surgery in people with Crohn's disease can actually lead to more problems.
There are several surgical options available for people with ulcerative colitis. Which one is right for you depends on several factors:
- The extent of your disease
- Your age
- Your overall health
The first option is called a proctocolectomy. It involves the removal of the entire colon and rectum. The surgeon then makes an opening on the abdomen called an ileostomy that goes into part of the small intestine. This opening provides a new path for feces to be emptied into a pouch that's attached to the skin with an adhesive.
Another commonly used surgery is called ileoanal anastomosis. The surgeon removes the colon and then creates an internal pouch that connects the small intestine to the anal canal. This allows feces to still exit through the anus.
Even though surgery will not cure Crohn's disease, about 50% of people with Crohn's require surgery at some point. If you have Crohn's disease and need surgery, your doctor will discuss your options with you. Be sure you ask questions and understand the goal or goals of the surgery, the pros and cons, and what could happen if you don't have the surgery.
When you have an IBD, the symptoms will come and go over a period of many years. That doesn't mean they control you. Managing your condition with the help of your health care providers is the best way to stay as healthy as possible in the long term.