The main difference between colitis and ulcerative colitis (UC) is the trigger. UC usually stems from an autoimmune reaction, while other types of colitis may result from an infection or medication use.

Colitis describes inflammation in the large intestine. Several conditions can lead to colitis, and UC is a common type.

Doctors also categorize colitis into additional subtypes. Subtypes of colitis, including UC, may have different causes, but symptoms often overlap.

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The main difference between colitis and UC is the cause.

UC usually develops due to an autoimmune reaction, which is when the body’s immune system attacks healthy tissue of the large intestines.

Other types of colitis may also develop due toTrusted Source infection or medications. The most common cause of medication-induced colitis is due to nonsteroidal inflammatory drugs (NSAIDs). Some cancer treatments, such as immunotherapy, induce an inflammatory response and colitis.

Another differentiating factor between UC and other types of colitis is how long the condition lasts. Although someone may experience a remission of symptoms, UC is a lifelong condition, while other forms of colitis may resolve.

As the colon becomes inflamed in both diseases, symptoms overlap between colitis and UC.

Symptoms of colitis includeTrusted Source:

Individuals with UC may also develop symptoms of inflammation outside the large intestine that those with colitis do not.

Additional symptoms from outside the intestine happen in 10% to 30% of people with UC and may includeTrusted Source:

  • eye inflammation
  • skin problems such as rashes and ulcers
  • joint pain and joint diseases

Doctors diagnose both UC and colitis using similar techniques.

After a review of symptoms, medical history, and physical exam, diagnostic tests help confirm a diagnosis. Tests mayTrusted Source include:

Treatment for UC may overlap with other forms of colitis and may include medication to manage diarrhea and treatment of inflammation of the intestine for both UC and colitis.

Additional treatment may depend on the specific type of cause of colitis. For instance, people with infectious colitis may require antibiotics. Someone with ischemic colitis may require medication to improve blood flow to the colon.

Although UC is the most common, there are other causes and forms of colitis. These include the following.

Ischemic colitis vs. UC

Ischemic colitis involves injury to the large intestine due to a lackTrusted Source of blood flow to the area.

The colon needs constant blood flow to remain healthy. When that blood flow becomes interrupted, it can damage the colon.

Doctors may associate ischemic colitis with certain co-occurring conditions, including:

Microscopic colitis vs. UC

According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)Trusted Source, microscopic colitis involves colon inflammation that is only visible using a microscope.

Medications such as NSAIDs are the most common cause of microscopic colitis.

Other possible causesTrusted Source include:

  • certain medications
  • smoking
  • genetics

Collagenous colitis vs. UC

Collagenous colitis is the second typeTrusted Source of microscopic colitis.

The colon also appears to be of typical thickness on a colonoscopy, but people with collagenous colitis develop collagen under the colon’s lining.

Lymphocytic colitis vs. UC

Lymphocytic colitis is one of two types of microscopic colitis.

People with lymphocytic colitis have microscopic tissue differences in the colon, including increasedTrusted Source white blood cells.

The colon’s lining is often of a typical thickness, while with UC, the large intestine becomes thicker than usual.

Infectious colitis vs. UC

Infectious colitis refers to inflammation in the colon due to a pathogen, such as bacteria, parasite, or virus.

In comparison, UC does not usually develop due to an infection, but in some casesTrusted Source, it may trigger an atypical immune response leading to UC.

Acute colitis vs. UC

Acute colitis means sudden, intense, or severe symptoms.

Not all people with UC have severe symptoms all the time, but acute symptoms do occur.

Pseudomembranous colitis vs. UC

Pseudomembranous colitis develops due toTrusted Source an infection with Clostridium difficile. This type of bacterium is usually present in the intestine.

Typically, the body has enough good bacteria to keep C. difficile at bay. However, if good bacteria decrease in number, C. difficile can lead to colon inflammation. Pseudomembranous colitis often occurs as a complication of antibiotic use.

Nonspecific colitis vs. UC

Nonspecific colitis refers to colitis that does not have the same features as any other type of colitis.

A small 2019 study found that many people with colitis had a diagnosis of nonspecific colitis. Of the 80 study participants, around 83% had a diagnosis of nonspecific colitis.

Segmental colitis vs. UC

Segmental colitis, such as left-sided colitis, involves a long term, nonspecific form of inflammation that only affects a limited section of the colon.

Doctors sometimes associate this condition with diverticulitis, which causes small pouches in the intestine lining.

Colitis and ulcerative colitis (UC) both involve inflammation of the large intestine. The diagnosis and treatment for both conditions tend to overlap.

The main difference between the two is the specific cause. UC results from an atypical reaction in the immune system. Colitis can have several different causes, such as infections or certain medications.

Visit our dedicated IBD hub for more resources on UC.