Ulcerative Colitis – Diagnosis, Symptoms, and Treatment

Doctor Nathan LeDeaux, MD

Medically reviewed by Dr. Nathan LeDeaux, MD

Medical Professional

Updated - January 11, 2021

Nathan LeDeaux is an emergency medicine physician at the University of Wisconsin and got his M.D. from Northwestern University in Chicago Illinois.

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What is Ulcerative Colitis?

Ulcerative colitis (UC) is an inflammatory bowel disease, these conditions are characterized by autoimmune injury and inflammation of the gastrointestinal tract. The other common inflammatory bowel disease, Chron’s disease also results from similar autoimmune injury but affects other areas of the body. These two conditions have significant overlap but also have unique features amongst them. Crohn’s disease may affect any portion of the gastrointestinal tract from the mouth down to the anus.  In contrast, ulcerative colitis typically only affects the large bowel (colon).

Patients with either of the inflammatory bowel diseases often experience episodic abdominal pain, bloating, nausea/vomiting, diarrhea, bloody stool, and mucous in the stool.  Patients may also develop long-term complications such as nutritional deficiencies, fistula formation, and colon cancer. Since many of these complications can be prevented with early detection and treatment understanding the symptoms and treatment of ulcerative colitis is critical.

What Causes Ulcerative Colitis?

Ulcerative colitis and Crohn's disease are autoimmune inflammatory diseases in which the immune system inappropriately attacks normal body tissue and organs – such as the gastrointestinal tract. Inflammatory bowel diseases are thought to result from a combination of genetic and environmental factors. 

There are multiple risk factors that are known to increase the risk of developing ulcerative colitis. The best studied of these are:

  • A first-degree relative with ulcerative colitis (a parent or sibling)
  • European and Jewish descent 
  • Living in areas with high levels of air pollution

It is unknown why these risk factors increase the chances of developing ulcerative colitis. It is thought that the balance of bacteria in the gut and the health of the cells that separate the intestinal space from the body play a critical role. 

The symptoms of ulcerative colitis are related to chronic inflammation in the colon that erodes the intestinal wall, reduces the absorption of nutrients, and can potentially lead to leakage of intestinal contents into other areas of the body. 

How Common is Ulcerative Colitis?

Ulcerative colitis is relatively rare in the United States. According to the United States Centers for Disease Control and Prevention, approximately 1 million U.S. adults are living with ulcerative colitis. 

Ulcerative colitis is more common in those between the ages of 15-30, those living below the poverty line, and those of Hispanic, European, or Jewish descent. 

Signs and Symptoms

The classic symptom of ulcerative colitis is bloody diarrhea, there are several other symptoms that are also common:

  • Abdominal pain
  • Sudden and repeated urge to defecate
  • Stool with large amounts of mucus

These symptoms generally begin gradually and commonly follow a relapsing and remitting course with periods of significant improvement followed by a sudden return of symptoms with no clear trigger. 

Since ulcerative colitis is an autoimmune disease that results in significant amounts of inflammation, the increased activity of the immune system can also affect other areas of the body. This results in symptoms such as fever, malaise, and weight loss.

The overactivation of the immune system can also result in more severe symptoms elsewhere in the body, only a minority of patients present with these symptoms. 

  • Inflammation of the eyes leading to redness and dryness
  • Joint pain and swelling 
  • Bruise and pimple-like lesions on the skin
  • Damage to the liver tissue and liver cancer

The most common complication of any inflammatory bowel disease is a reduction in the absorption of vital nutrients, fats, and proteins. This can result in a wide variety of conditions such as heart disease, weight loss, low bone density, and damage to the teeth, hair, and nails. 

A subset of patients will develop toxic megacolon, a condition that results in the death of intestinal tissue – these patients are generally very ill and present with severe symptoms such as a rigid and extremely painful abdomen, loss of consciousness, low blood pressure, and even death


The diagnosis of ulcerative colitis is made by reviewing your medical history, your current symptoms, supportive tests, and imaging of the colon via a colonoscopy. 

Testing often begins with a stool sample to rule out acute infection by bacteria or parasites and basic lab tests such as a CMP (comprehensive metabolic panel), CBC (complete blood cell count), and coagulation studies (PT/INR, PTT).  Your doctor will usually check your stool for Clostridium difficile toxin prior to performing colonoscopy in order to rule out C. difficile colitis – this is an infectious form of colitis that can mimic or coexist with inflammatory bowel disease.

The colonoscopy is typically performed after other conditions are ruled out.  During this procedure, your doctor will visualize the lower gastrointestinal tract by providing you with sedation and advancing a camera up the anus and through the colon. 

If the diangosis is not clear based on colonoscopy alone your doctor may perform an upper endoscopy which is similar but is used to evaluate the stomach and small intestine by inserting a scope through the mouth.

Your doctor may recommend a radiographic study in which they have you swallow contrast and perform a CT scan or MRI – this test is obtained in order to evaluate the portion of the bowel that cannot be visualized with upper and lower endoscopy.

Ulcerative Colitis Medication 

The treatment of ulcerative colitis is based on reducing the activity of the immune system in and around the colon. This reduces inflammation and allows your colon to heal. 

The medications Azulfidine (sulfasalazine) and 5-aminosalicylate are first-line for the treatment of ulcerative colitis and lead to remission of the disease in nearly 50% of patients. These medications reduce the activity of the immune system, leading to a decrease in the inflammation of the colon wall. If these medications do not lead to remission of your symptoms within 2 weeks short-term oral or intravenous corticosteroids are typically started for several days to weeks. The most common of which are Orapred (Prednisone) and Solumedrol (Methylprednisolone).

If your symptoms do not respond to a combination of the above medications may be started on alternative agents such as oral mesalamine, which is available as Pentasa, Asacol, or Canasa.

If you have ulcerative colitis symptoms that are limited to the anus (proctitis)  you may be prescribed mesalamine rectal suppositories.  Occasionally these will not sufficiently relieve symptoms and the use of Rowasa (Mesalamine enemas) will be required.  Cortenema and Colocort (Corticosteroid enemas) may also be beneficial in some patients.

In more severe or recurrent cases of inflammatory bowel disease, your doctor may recommend long-term treatment with Imuran (Azathioprine).  Occasionally, they will prescribe Neoral (Cyclosporine) or Entyvio(Vedolizumab) which work in a manner similar to the first-line medications listed above but have a higher risk of side effects due to their strong effects on the immune system.



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The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.