Colitis is inflammation of the lining of the colon. Many different conditions can cause this, including ulcerative colitis and Crohn’s disease, which are types of inflammatory bowel disease.

The most common type of colitis is ulcerative colitis (UC), which causes ulcers or sores to develop in the stomach. The inflammation extends from the rectum along the inner lining of the colon.

Although the types and causes of colitis may differ, most symptoms overlap. How the condition affects an individual varies from person to person.

This article discusses the different types of colitis, its causes and risk factors, and when to contact a doctor.

Woman with colitis holding her hands on her stomach.Share on Pinterest
CocoSan/Getty Images

Colitis refers to inflammation within the lining of the colon. This can occur due to several different conditions. The main two are UC and Crohn’s disease, which are types of inflammatory bowel disease (IBD).

Colitis is often a lifelong condition, and there is currently no cure. However, treatment options are available to help manage the condition.

Colitis typically develops when people are between 20 and 30 years old or over 60.

UC is the most common variation of colitis. It begins in the rectum and spreads up the colon in different ways, depending on the type.

People with chronic UC may experience episodes of acute severe colitis during their lifetime.

Acute severe UC is a condition that can be life threatening and almost always requires hospitalization to balance fluids and electrolytes and, in some cases, to obtain nutritional support.

According to a 2023 study, approximately 9.24% of people with IBD experience hospitalizations due to IBD-related causes, which may include colitis flare-ups.

Some types of UC include:

Ulcerative proctitis

This type of colitis is limited to the rectum. The Crohn’s & Colitis Foundation notes there is no increased risk of cancer.

Symptoms of ulcerative proctitis can include:

Left-sided colitis

Inflammation begins at the rectum and continues along the left side of the colon. It can also include proctosigmoiditis, which affects the rectum and lower part of the colon above the rectum, or the sigmoid colon.

Symptoms of left-sided colitis may include:

Extensive colitis

This condition affects most of the colon. In the case of pancolitis, it affects all of the colon.

Symptoms of extensive colitis include:


UC can occur due to:

Crohn’s colitis is one of several types of Crohn’s disease. Unlike other variations of the condition, Crohn’s colitis only affects the colon.

Symptoms overlap between Crohn’s conditions, but people with Crohn’s colitis are more likely to develop skin lesions and joint pain.

Some other symptoms include:


Crohn’s colitis may occur due to:

A healthcare professional can only see microscopic colitis with a microscope.

There are two types of microscopic colitis: lymphocytic and collagenous.

With the lymphocytic type, there are a higher number of white blood cells than usual, and the colon lining is of a standard thickness.

With the collagenous type, the layer of collagen under the epithelium is thicker than usual.

The symptoms of each type are similar. A person will typically experience watery diarrhea that does not contain blood.

Some other signs and symptoms include:


Microscopic colitis may occur due to:

Autoimmune conditions

In these cases, a person’s immune system attacks its own cells. Autoimmune conditions that may be a cause include:


Medications that may be associated with microscopic colitis include:

  • NSAIDs, such as aspirin
  • acarbose
  • lansoprazole
  • sertraline (Zoloft)
  • ranitidine
  • ticlopidine


Bacterial and viral infections may cause inflammation of the gastrointestinal tract.

Bile acid malabsorption

Bile acid is a fluid that helps carry waste out of the body.

Bile acid malabsorption occurs when the intestines are unable to reabsorb the bile acid. If it reaches the colon, it can lead to diarrhea.

Another type of colitis is ischemic colitis. It occurs due to reduced blood flow to the colon.

A person may experience abdominal cramping, pain, and bloody stools.

Other ischemic colitis symptoms include:

A 2015 article states that there are three main categories of ischemic colitis:

  • gangrenous
  • stricturing
  • transient

Most people have the transient type, which causes milder symptoms, but some have the gangrenous type.

Gangrenous ischemic colitis is particularly severe. People with this condition are likely to require surgical intervention when symptoms appear.


Ischemic colitis occurs when there is a lack of blood flow to the colon. This can happen for various reasons, such as heart disease and other conditions that affect blood flow.

Pseudomembranous colitis is usually the result of Clostridioides difficile bacteria.

These bacteria are always present in the body, but there are usually enough “good” bacteria to override them.

When these good bacteria die, often after a person has taken antibiotics, the presence of C. difficile increases, causing inflammation in the colon.


Pseudomembranous colitis can occur due to taking medications that destroy healthy bacteria, such as antibiotics.

Colitis can also result from conditions unrelated to IBD. One such condition is cytomegalovirus (CMV), which is a common strain of the herpes virus.

One 2023 article notes that symptoms can be nonspecific and mimic those of IBD. However, a person may experience:

  • abdominal pain
  • diarrhea
  • fever
  • rectal bleeding
  • weight loss
  • feelings of discomfort

Rectal bleeding and diarrhea appear to be the most common symptoms.

If a person with CMV develops symptoms of colitis, they should contact a doctor as soon as possible.


CMV is a strain of the herpes virus that affects approximately 70% of the general population. It does not typically cause any symptoms.

However, symptoms can occur, especially in those with a compromised immune system.

Treatment options will depend on the type and severity of symptoms that a person is experiencing.

There are different types of medications that a doctor may suggest, including:

If medication does not work, the doctor may suggest surgical intervention.

Surgery may also be desirable to people who are benefiting from medication but still find that the condition affects their quality of life.

There is no way to prevent colitis. However, a person can take steps to help manage the condition and reduce its symptoms.

These steps may include:

Research indicates that people who smoke are twice as likely to experience IBD than people who do not smoke. This is due to a certain protein in the lungs that smoking can activate.

Learn more about natural remedies for managing ulcerative colitis.

Colitis is not typically fatal. However, it is a lifelong condition that can have life threatening complications.

For example, some types of colitis — such as Crohn’s disease or UC — can increase the risk of developing colon cancer. Microscopic colitis, on the other hand, does not increase the risk of developing colon cancer.

Additionally, a person’s outlook depends on the type of colitis they have.

For example, with CMV colitis, the outcome is favorable. It can even resolve without antiviral treatment in approximately 25% of people.

Learn more about the potential complications of ulcerative colitis.

It is always best for a person to make a doctor aware if they believe that they have colitis. Even if medical treatment does not seem necessary, the support can be beneficial.

People should contact a doctor if they experience any of the following symptoms:

  • abdominal pain or cramping
  • bloody diarrhea
  • an urgent need to have a bowel movement
  • blood in the stool
  • rectal bleeding
  • weight loss

If a person thinks they may have acute severe UC, they need medical attention immediately.

What are the main causes of colitis?

The main causes of colitis are:

  1. Infections: Bacterial, viral, or parasitic infections.
  2. Inflammatory bowel disease (IBD): Includes UC and Crohn’s disease.
  3. Ischemia: Reduced blood flow to the colon.
  4. Medications: Certain drugs such as NSAIDs and antibiotics.
  5. Microscopic colitis: Includes collagenous colitis and lymphocytic colitis.

Does colitis ever go away?

Whether colitis goes away depends on the type and underlying cause of the condition.

Infectious and medication-induced colitis often resolves with appropriate treatment or discontinuation of the medication in question.

With treatment, a person can manage chronic conditions such as UC and Crohn’s disease to achieve remission, but they are typically lifelong conditions with the potential for flare-ups.

What happens when you have colitis?

When a person has colitis, their colon becomes inflamed, which leads to symptoms such as:

  • diarrhea
  • abdominal pain
  • blood in the stool
  • urgency to have bowel movements
  • fatigue
  • sometimes fever

The severity and specific symptoms depend on the type of colitis.

Infectious colitis often includes nausea and vomiting, while chronic conditions such as UC and Crohn’s disease may cause extraintestinal symptoms such as joint pain and skin rashes.

What are the first symptoms of colitis?

The first symptoms of colitis typically include:

  • Diarrhea: Often the initial and most common symptom.
  • Abdominal pain and cramping: Usually felt in the lower abdomen.
  • Blood in stool: Ranging from small amounts to significant bleeding.
  • Urgency to have a bowel movement: A frequent and urgent need to use the bathroom.
  • Fatigue: Resulting from the body’s inflammatory response and fluid loss.
  • Fever: Particularly if the colitis is due to an infection.

These symptoms can appear suddenly or develop gradually, depending on the cause of the colitis.

When the inner lining of the colon becomes inflamed, it is known as colitis.

This can be the result of several conditions. However, the most common type is UC.

If a person develops colitis, they are likely to experience abdominal discomfort, rectal bleeding, weight loss, bloody diarrhea, and an urgent need to have a bowel movement.

A person should contact a doctor if they suspect they have colitis.

Read this article in Spanish.