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Ulcerative colitis vs. Crohn’s: Compare causes, symptoms, treatments, & more

Ulcerative colitis and Crohn’s disease are two major types of inflammatory bowel disease (IBD). Compare the differences in diagnosis, treatments, and prevention of ulcerative colitis and Crohn's.

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Ulcerative colitis and Crohn’s disease are two major types of inflammatory bowel disease (IBD). Both conditions are marked by chronic inflammation of the gastrointestinal (GI) tract, which can lead to symptoms such as diarrhea and abdominal pain. Chronic inflammation typically arises as a result of the immune system’s response to bacteria in the gut or other environmental triggers, such as certain foods. 

Ulcerative colitis is characterized by inflammation in the colon, or large intestine. Crohn’s disease is characterized by inflammation that can develop in any part of the gastrointestinal tract from the mouth to the anus, although it primarily affects the small intestine. In ulcerative colitis, inflammation remains in the inner lining of the colon while in Crohn’s disease, inflammation can spread to deeper layers of the bowel wall. In addition, continuous inflammation is found throughout the colon in ulcerative colitis whereas inflamed areas, or skip lesions, may be found in between patches of healthy tissue in Crohn’s disease. 

Continue reading to learn more about key differences and similarities between ulcerative colitis and Crohn’s. 

Causes

Ulcerative colitis

The exact cause of ulcerative colitis is unknown. Inflammation develops when the body’s own immune system incorrectly responds to bacteria, viruses, or fungi found in the colon, which leads to healthy tissue damage. Ulcerative colitis is considered to be an autoimmune, inflammatory disorder that can be triggered by environmental and genetic factors. 

Crohn’s

The exact cause of Crohn’s disease is also unknown. The immune system attacks intestinal flora, which then leads to inflammation of the colon and damage to intestinal tissue. Like ulcerative colitis, Crohn’s is linked to environmental and genetic factors. However, genetics may play a larger role with Crohn’s than with ulcerative colitis. Those who have a family history of Crohn’s may be more likely to develop the disease than those without an affected relative. 

Ulcerative colitis vs. Crohn’s
Ulcerative colitis Crohn’s disease
  • The exact cause is unknown but potential causes could be attributed to genetics and environmental factors.
  • The exact cause is unknown but potential causes could be attributed to genetics and environmental factors.

Prevalence

Ulcerative colitis

Approximately 907,000 Americans have ulcerative colitis. Although it typically affects people between the ages of 15 and 35, ulcerative colitis can occur at any age. The median age of diagnosis for ulcerative colitis is 35 years old. Ulcerative colitis is more common in men than in women, and more men are diagnosed in their 50s and 60s than women who are of the same age. 

Crohn’s

Approximately 780,000 Americans have Crohn’s disease. On average, Crohn’s disease also affects people between the ages of 15 and 35. However, the median age of diagnosis for Crohn’s is 30 years old. Crohn’s disease is diagnosed more often in women than in men. Women are 1.1 to 1.8 times more likely to be diagnosed with Crohn’s than men. 

Ulcerative colitis vs. Crohn’s
Ulcerative colitis Crohn’s disease
  • 907,000 Americans
  • Median age of diagnosis: 35 years old
  • More common in men than in women
  • Common in urban areas and northern climates
  • 780,000 Americans
  • Median age of diagnosis: 30 years old
  • More common in women than in men
  • Common in urban areas and northern climates

Symptoms

Ulcerative colitis

The most common symptoms of ulcerative colitis are diarrhea, abdominal pain, rectal bleeding, an urgency to pass stool, and constipation, or an inability to pass stool despite an urgent need. Other symptoms may include fatigue, fever, reduced appetite, and weight loss. Compared to Crohn’s, ulcerative colitis is more likely to cause bleeding in the rectum

Complications of ulcerative colitis include severe bleeding, rapid swelling of the colon (toxic megacolon), a hole in the colon (perforated bowel), and bone loss (osteoporosis).

Crohn’s

The most common symptoms of Crohn’s disease are diarrhea, abdominal pain, rectal bleeding, urgent bowel movements, and constipation. Other common symptoms include fatigue, fever, reduced appetite, and weight loss. Compared to ulcerative colitis, Crohn’s disease is more likely to cause weight loss. Mouth sores and perianal pain caused by fistulas, or tunnels from one part of the intestine to the skin, are other common symptoms of Crohn’s disease. 

Complications of Crohn’s disease include a perforated bowel, open sores, abscesses (or pus collecting in the digestive tract), fistulas, anal fissures, strictures, and malnutrition. 

Ulcerative colitis vs. Crohn’s
Ulcerative colitis Crohn’s disease
  • Diarrhea
  • Abdominal pain
  • Rectal bleeding
  • Urgency to pass stool
  • Inability to pass stool despite urgency
  • Fatigue
  • Fever
  • Reduced appetite
  • Weight loss
  • Diarrhea
  • Abdominal pain
  • Rectal bleeding
  • Urgency to pass stool
  • Inability to pass stool despite urgency
  • Fatigue
  • Fever
  • Reduced appetite
  • Weight loss
  • Mouth sores
  • Perianal pain

Diagnosis

Ulcerative colitis

Ulcerative colitis is typically diagnosed through the use of lab tests, endoscopic procedures, and imaging procedures. Blood tests can help identify anemia, or a low number of healthy red blood cells, and inflammatory proteins that can indicate ulcerative colitis. Stool studies can help determine the presence of an infection caused by bacteria, viruses, or parasites in the GI tract. Imaging procedures like X-rays, CT scans, and MRIs can help identify any complications from ulcerative colitis. A biopsy will be performed through a colonoscopy to confirm a diagnosis. 

Crohn’s

Crohn’s disease is also diagnosed through the use of lab tests, endoscopic procedures, and imaging procedures. Blood tests and stool samples can help rule out other conditions or infections. X-rays, CT scans, and MRIs can help identify the presence of certain complications from Crohn’s, such as fistulas, strictures, or perforated bowels. An endoscopy can assist a doctor in visualizing part of the GI tract. A colonoscopy can help confirm a diagnosis. 

Ulcerative colitis vs. Crohn’s
Ulcerative colitis Crohn’s disease
  • Blood tests
  • Stool studies
  • X-ray
  • CT scan
  • MRI
  • Colonoscopy
  • Blood tests
  • Stool studies
  • X-ray
  • CT scan
  • MRI
  • Colonoscopy

Treatments

Ulcerative colitis

Treatment for ulcerative colitis depends on the severity of the disease. First-line agents for ulcerative colitis include anti-inflammatory medications, such as aminosalicylate agents and corticosteroids. Examples of aminosalicylates include Asacol HD (mesalamine) and Azulfidine (sulfasalazine). Examples of corticosteroids include Deltasone (prednisone) and Entocort (budesonide). Immunosuppressants or biologic medications may be prescribed if other treatments are ineffective. Remicade (infliximab) is a biologic medication, also classified as a TNF-alpha inhibitor, that may be prescribed for ulcerative colitis. 

Around 20% of people with ulcerative colitis will require a total colectomy, or surgical removal of the entire colon. Experimental treatments are currently being studied for ulcerative colitis, such as heparin and butyrate. 

Crohn’s

Treatment for Crohn’s disease also depends on the severity of the disease. Aminosalicylate agents and corticosteroids are first-line treatments for Crohn’s disease. Immunosuppressants or biologic agents may be prescribed for those who are uncontrolled with aminosalicylates and corticosteroids. Immunosuppressants, like Purinethol (mercaptopurine), Imuran (azathioprine), and Trexall (methotrexate), or biologics, such as Remicade (infliximab), may be necessary for those with moderate to severe disease. 

Surgery may be required for patients who develop fistulas. Experimental treatments are currently being studied for Crohn’s, such as thalidomide and interleukin (IL)-11. 

Ulcerative colitis vs. Crohn’s
Ulcerative colitis Crohn’s disease
  • Aminosalicylates
  • Corticosteroids
  • Immunosuppressants
  • Biologics
  • Surgery
  • Butyrate
  • Heparin
  • Aminosalicylates
  • Corticosteroids
  • Immunosuppressants
  • Biologics
  • Surgery
  • Thalidomide
  • Interleukin (IL)-11

Risk factors

Ulcerative colitis

Risk factors for developing ulcerative colitis include a family history of the disease and environmental triggers. Those with a first-degree relative affected by ulcerative colitis are more likely to get ulcerative colitis. The use of antibiotics and nonsteroidal anti-inflammatory drugs (NSAIDs) may also increase the risk of getting ulcerative colitis. Lifestyle factors, such as diet, may trigger a flare-up of ulcerative colitis. 

Crohn’s

A family history of Crohn’s disease is a strong risk factor for developing the condition. The use of antibiotics and NSAIDs can also increase the risk of Crohn’s disease. Although smoking tobacco has been found to have protective effects against the development of ulcerative colitis, smoking tobacco is considered a risk factor for developing Crohn’s disease. Children who have had their appendix removed (appendectomy) may be at higher risk of getting Crohn’s later on in life. Diet can also play a role in triggering flare-ups in those with Crohn’s disease. 

Ulcerative colitis vs. Crohn’s
Ulcerative colitis Crohn’s disease
  • Family history
  • Antibiotics
  • NSAIDs
  • Diet
  • Family history
  • Antibiotics
  • NSAIDs
  • Diet
  • Smoking tobacco
  • Appendectomy

Prevention

Ulcerative colitis

Because ulcerative colitis does not have a defined cause, there is no proven way to prevent ulcerative colitis. Your genetic predisposition to getting ulcerative colitis cannot be prevented. However, lifestyle changes may help decrease the incidence of flare-ups. Avoiding foods that trigger flare-ups, quitting smoking, drinking enough fluids, and regularly exercising may help prevent flare-ups. 

Crohn’s

Crohn’s cannot be prevented through any single method since the development of the disease is heavily influenced by genetics. Living a healthy lifestyle and finding out which foods trigger a flare-up may help decrease the frequency of flare-ups. Quitting smoking, drinking plenty of fluids, and regularly exercising are other examples of ways to prevent flare-ups. 

Ulcerative colitis vs. Crohn’s
Ulcerative colitis Crohn’s disease
  • Avoiding triggering foods
  • Drinking enough fluids
  • Regularly exercising
  • Quitting smoking
  • Reducing stress
  • Taking prescribed medications
  • Visiting your doctor regularly
  • Avoiding triggering foods
  • Drinking enough fluids
  • Regularly exercising
  • Quitting smoking
  • Reducing stress
  • Taking prescribed medications
  • Visiting your doctor regularly

When to see a doctor for ulcerative colitis or Crohn’s

If you experience any signs or symptoms of inflammatory bowel disease, you should seek the help of a healthcare provider. Your primary care provider may recommend a gastroenterologist who will confirm a diagnosis. These conditions can progress into more severe forms of the disease. Ulcerative colitis and Crohn’s disease can also increase the risk of colon cancer. Therefore, prompt treatment is recommended to manage these conditions and improve quality of life. 

Frequently asked questions about ulcerative colitis and Crohn’s

How does diet affect ulcerative colitis and Crohn’s disease?

Certain foods may trigger a flare-up. Foods that trigger flare-ups will vary among people with inflammatory bowel disease. In general, however, foods that are greasy, fried, spicy, caffeinated, or sugary can potentially trigger a flare-up. Alcohol may also trigger symptoms in some people. 

Can ulcerative colitis and Crohn’s disease be cured?

There is no known cure for ulcerative colitis or Crohn’s disease. However, these conditions can be managed with proper treatment, medications, and lifestyle changes. 

Can I live a normal life with ulcerative colitis or Crohn’s disease?

It can be difficult to live with inflammatory bowel disease. Conditions like ulcerative colitis and Crohn’s disease can be mentally and physically draining. Still, many people with these conditions live a relatively normal life when they stick to an effective treatment plan. 

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