Crohn’s Disease

Crohn’s disease is a lifelong inflammatory condition that can affect any part of your digestive system, most commonly the small intestine and colon. While there is no cure, treatments can help control symptoms and allow you to live an active, fulfilling life.

Table of contents

• What is Crohn’s Disease?
• Types of Crohn’s Disease
• Signs and Symptoms
• Complications
• Causes and Risk Factors
• How is Crohn’s Disease Diagnosed?
• Treatment Options
• Living with Crohn’s Disease

What is Crohn’s Disease?

Crohn’s disease is a chronic, or long-lasting, condition that causes inflammation (swelling) in your digestive tract^[1]. Inflammation means your body’s immune system is reacting and causing tissue to become red, swollen, and painful. Unlike some digestive problems that only affect the surface layer of your intestines, Crohn’s disease affects the entire thickness of the bowel wall^[3].

Crohn’s disease is one of the main types of inflammatory bowel disease (IBD), which is different from irritable bowel syndrome^[2]. The condition can affect any part of your digestive tract, which runs from your mouth all the way to your anus. However, it most commonly affects your small intestine and the beginning of your large intestine (colon)^[5].

• Small intestine (ileum)
• Large intestine (colon)
• Stomach
• Esophagus
• Mouth

This is a lifelong disease that runs in cycles. You may have periods when symptoms are active, called flare-ups or flares, and other times when you have few or no symptoms, called remission^[2]. More than three-quarters of a million people in the United States have Crohn’s disease, affecting approximately 6 to 8 million people globally^[2].

Types of Crohn’s Disease

The disease can appear in different patterns depending on which part of your digestive tract is affected. Understanding your type helps doctors plan the best treatment for you^[2].

Ileocolitis is the most common type. It causes inflammation in your lower small intestine and part of your large intestine^[2].

Ileitis involves swelling and inflammation only in your small intestine, specifically the part called the ileum^[2].

Colitis means inflammation occurs in the lining of your large intestine only^[2].

Gastroduodenal Crohn’s disease affects your stomach and the top part of your small intestine called the duodenum^[2].

Jejunitis causes patchy areas of inflammation in the upper half of your small intestine, the part called the jejunum^[2].

Perianal disease occurs when inflammation develops around the anus, which can cause fistulas (abnormal tunnels) and abscesses (pockets of infection)^[2].

Research from Minnesota shows that about one-third of patients have disease in the ileum alone, one-third in both the ileum and colon, and one-third in the colon only^[3]. The location of your disease can affect your risk of developing certain complications.

Signs and Symptoms

Symptoms of Crohn’s disease can vary widely from person to person. They may develop gradually or come on suddenly, and can range from mild to severe^[2]. Some people have chronic symptoms until a doctor successfully treats them, while others have symptoms that come and go.

The most common symptoms include diarrhea and cramping or pain in your abdomen^[1]. Many people also experience weight loss, which happens because inflammation can make it difficult for your body to absorb nutrients from food^[5].

Other frequent symptoms are bloody stool, mouth ulcers or pain in your mouth or gums, fever, and fatigue (tiredness that doesn’t improve with rest)^[2]. You may also notice a loss of appetite or abscesses and infections around your anal canal^[2].

Because Crohn’s disease causes inflammation throughout your body, it can affect areas outside your digestive system. These symptoms may include arthritis or joint pain, skin rashes, eye inflammation (such as uveitis and episcleritis), kidney stones, osteoporosis (loss of bone mass), skin tags around your anus, and inflammation in your bile ducts^[2].

In children, Crohn’s disease can cause growth delays or failure to grow properly^[2]. The condition may initially present with nonspecific symptoms, and some people may not have a clear family history, which means diagnostic delays are not uncommon^[3].

Stress and eating certain foods don’t cause the disease, but they can make your symptoms worse^[5]. Some people find that carbonated drinks and high-fiber foods may trigger symptoms^[5].

Complications

Crohn’s disease can cause serious complications that may require additional treatment or surgery. Understanding these complications helps you recognize when to seek immediate medical care^[2].

Fistulas are abnormal tunnel-like openings that connect two body parts that don’t normally connect. When ulcers (open sores) extend completely through the intestinal wall, they can create these painful passageways. For example, fistulas sometimes create an opening between your rectum and the skin surrounding your anus^[4]. These can become infected and fill with pus, forming an abscess^[4].

Abscesses are pus-filled pockets of infection that form in your digestive tract or abdomen. They happen when an area damaged by inflammation gets infected, forming a swollen and painful pocket^[2].

Bowel obstructions occur when your intestine becomes partially or completely blocked. This can happen when inflammation thickens the intestinal walls or when scar tissue forms from repeated cycles of inflammation and healing^[2]. Complete intestinal obstructions can become life-threatening if left untreated^[4].

Anal fissures are small tears in your anus that happen when inflammation creates damage in the tissue lining. These cause pain, itching, and bleeding, especially during bowel movements^[2].

Ulcers are open sores that can develop in your mouth, intestines, anus, or the area between your genitals and anus. These result from deep inflammation moving outward through the intestine wall^[5].

Malnutrition can develop when inflammation affects parts of your digestive tract that absorb nutrients. This means your body doesn’t get the right amount of vitamins, minerals, and nutrients it needs to stay healthy^[5].

There is an increased risk of cancer in affected segments of your intestine. Patients with colonic involvement have a long-term risk of colorectal cancer, particularly with extensive and long-standing disease^[7]. Chronic malabsorption may cause nutritional deficiencies, particularly of vitamins D and B12^[7].

Causes and Risk Factors

The exact cause of Crohn’s disease is unknown. However, researchers believe it results from a combination of factors rather than a single cause^[5].

An autoimmune reaction may be one cause. This happens when your immune system attacks healthy cells in your body by mistake. In Crohn’s disease, your immune system may be reacting abnormally to microorganisms in your digestive tract, but in the process, it also attacks your own tissues^[3].

Genetics appears to play a role, since Crohn’s disease can run in families. If you have a parent, child, or sibling with the disease, you are at higher risk. However, this family connection is only seen in about 20% of cases^[1].

Several factors may raise your risk of developing Crohn’s disease. Smoking may double your risk, and it also makes the disease worse if you already have it^[5]. Age is also a factor, as most people are diagnosed before age 30, though it can show up at any stage of life^[1].

Certain medicines may slightly increase your chance of developing Crohn’s disease, including antibiotics, birth-control pills, and nonsteroidal anti-inflammatory drugs like aspirin or ibuprofen^[5]. A high-fat diet may also slightly increase your risk^[5].

Environmental factors and where you live may influence your risk. Living in a developed country appears to increase risk^[6]. Stress doesn’t cause the disease, but it can worsen symptoms^[5].

How is Crohn’s Disease Diagnosed?

Your healthcare provider will likely diagnose Crohn’s disease only after ruling out other possible causes for your symptoms. There is no single test to diagnose the condition, so doctors use a combination of tests to confirm a diagnosis^[8].

The diagnostic process typically begins with a medical history, which includes asking about your symptoms and when they occur. Your doctor will also ask about your family history, since having relatives with the disease puts you at higher risk^[5].

A physical exam is an important part of diagnosis. Your doctor will check for bloating in your abdomen, listen to sounds within your abdomen using a stethoscope, and tap on your abdomen to check for tenderness and pain. They will also check if your liver or spleen is abnormal or enlarged^[5].

Blood tests can check for signs of infection or anemia, which is a condition where you don’t have enough red blood cells. These tests also measure levels of inflammation, check liver function, and look for the presence of inactive infections like tuberculosis^[8].

Stool tests can look for blood or organisms in your stool, such as infection-causing bacteria or parasites. Sometimes testing for stool markers of inflammation, such as calprotectin, can be helpful^[8].

Colonoscopy is a key procedure for diagnosing Crohn’s disease. During this test, doctors use a tiny camera on the end of a flexible tube to visually examine your entire colon and the very end of your small intestine. Small samples of tissue, called a biopsy, may be taken for laboratory analysis. Clusters of inflammatory cells called granulomas may suggest a diagnosis of Crohn’s disease, although these are not detected in about half of patients^[8].

Imaging tests provide detailed pictures of your digestive tract. A CT scan (computed tomography) is a special X-ray technique that looks at the entire bowel as well as tissues outside the bowel. CT enterography is a special CT scan that provides better images of the small bowel^[8]. An upper GI series uses a special liquid called barium and X-rays to make your upper digestive tract more visible^[5].

Endoscopy procedures allow doctors to look inside your digestive tract. An upper GI endoscopy uses a scope to look inside your mouth, esophagus, stomach, and small intestine^[5].

Treatment Options

There is no cure for Crohn’s disease, but treatments can decrease inflammation in your intestines, relieve symptoms, and prevent complications. The goals of treatment are to achieve the best possible control of the inflammatory disease with the least side effects from medication, and to permit you to function as normally as possible^[9].

Treatment approaches vary based on the disease site, pattern, activity, and severity. No single treatment works for everyone, so you and your provider will work together to find what’s best for you^[5].

Medicines are the main treatment for most people with Crohn’s disease. Many people will need medicines long-term. Which medicines your doctor prescribes depends on your symptoms, where the disease is causing inflammation, and other factors^[9].

Corticosteroids, also called steroids, reduce inflammation quickly but should only be used short term. They are effective for alleviating signs and symptoms of moderately to severely active Crohn’s disease^[12].

Immunosuppressants work by modifying your body’s immune system activity to stop it from causing ongoing inflammation. Thiopurines, such as azathioprine and 6-mercaptopurine, are effective and should be considered for use to reduce the need for steroids^[12].

Biologics are substances made from living organisms and given by infusion or injection. Anti-TNF agents (tumor necrosis factor blockers) like infliximab, adalimumab, and certolizumab pegol have significantly advanced treatment and improved the ability to achieve and maintain remission in patients with moderate to severe disease^[12]. Other biologics include interleukin blockers like ustekinumab, mirikizumab, and risankizumab^[11].

A new type of medicine called JAK inhibitors (Janus kinase inhibitors) work by targeting proteins involved in inflammation. These oral medicines may be prescribed for adults with Crohn’s disease who don’t respond to other medicines^[9].

Antibiotics can decrease anal fistula discharge and may induce remission. They should not be restricted in order to prevent disease flares^[12].

Bowel rest may be needed if you are in the hospital with complications. Your doctor may suggest resting your bowel for a few days to several weeks. This might involve drinking only certain liquids, receiving liquid nutrients through a feeding tube, or getting nutrients through a special tube inserted into a vein^[9].

Surgery is sometimes necessary even with medicines. Between 30% and 55% of people with Crohn’s disease will require surgery within 10 years after diagnosis^[9]. Surgery will not cure Crohn’s disease, but it can treat complications and improve symptoms. Doctors most often recommend surgery to treat fistulas, abscesses, bleeding that is life-threatening, intestinal obstructions, or inflammation and symptoms that don’t improve with medicines^[9]. Different types of operations can be performed, including small bowel resection to remove part of your small intestine^[9].

Living with Crohn’s Disease

Living with Crohn’s disease has its challenges, but you can still get the most out of life. With proper management and planning, many people with Crohn’s lead active, fulfilling lives^[19].

Managing flare-ups requires recognizing symptoms early. Tracking your symptoms helps you understand your baseline at remission and how your disease manifests when more active. Smartphone apps can help you monitor bowel movements, symptoms, and medications^[17]. Contact your doctor at the first sign of a flare so they can test for infections or determine if medications need adjustment^[17].

Diet and nutrition play an important role in managing Crohn’s disease. There is no specific diet that prevents or treats the condition, but certain strategies help control symptoms. Keep a record of foods you eat and note when symptoms worsen to help identify problem foods^[21]. During flare-ups, following a low-residue diet may help relieve abdominal pain and diarrhea. Avoid foods that increase stool output, such as fresh fruits and vegetables, prunes, and caffeinated beverages^[21]. Patients often find that smaller, more frequent meals are better tolerated^[21].

Exercise and staying active are important parts of a healthy lifestyle. Physical activity can help reduce stress, maintain healthy weight, and strengthen your immune system. Low-impact activities like walking may be best if you’re experiencing symptoms^[19].

Planning ahead helps you maintain independence. Know where to find clean bathrooms when you’re out. Keep an emergency kit with toilet paper, wet wipes, hand sanitizer, and clean clothes in your car, desk, or backpack^[16]. Eat more small meals instead of three big meals, especially when on the road or when you don’t have easy access to bathrooms^[18].

Managing stress is important because stress can worsen symptoms. Consider taking a stress reduction class or working with a mental health professional^[18].

Avoiding certain substances helps protect your digestive system. Quit smoking, as smoking is a strong risk factor that worsens Crohn’s disease^[17]. Avoid nonsteroidal anti-inflammatory medications like ibuprofen or naproxen, as these can impair your digestive tract’s ability to protect and heal itself. If you have pain, take acetaminophen instead^[17].

Work and daily activities can continue with some accommodations. Federal and state laws protect people with inflammatory bowel disease at work, which means you can speak to HR or your manager about reasonable accommodations you might need^[19].

Relationships and intimacy may be affected by the disease. Having open and honest relationships with those around you creates understanding and support. If you’re planning a family or interested in becoming pregnant, talk to your doctor about how medications could affect you and work to keep your disease under control for a healthy pregnancy^[19]. If your disease isn’t active, chances are you can get pregnant as easily as other women your age. The best time to conceive is when you’ve been in remission for at least 3 to 6 months^[16].

Support systems make a difference. Look to friends, family, or co-workers who can help when you need it most. Support groups filled with people who share similar experiences can provide understanding and practical tips^[19].