Beyond Ulcerative Colitis: Other Types of Colitis Explained

Ulcerative colitis (UC) is perhaps the most well-known type of colitis. But other types exist, and some are quite different from UC. We break them down.

If you’ve heard the term “ulcerative colitis” in connection with a diagnosis of inflammatory bowel disease, you might wonder whether “colitis” is the same thing.

“Colitis” is an umbrella term for a group of chronic digestive diseases involving inflammation of the inner lining of the colon.

Ulcerative colitis (UC) is just one type of colitis. Other types include:

• microscopic colitis
• pseudomembranous colitis
• ischemic colitis
• allergic colitis

The underlying cause of colitis determines its type.

They share some similarities but also some important distinctions.

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Ulcerative colitis

Ulcerative colitis (UC) is the most common inflammatory bowel disease (IBD). It’s a form of idiopathic chronic inflammation in the colon. “Idiopathic” means it happens with no known cause.

The chronic inflammation in the colon causes erosion of its lining, leading to bleeding.

Symptoms

Common UC symptoms include:

• abdominal pain
• blood or pus in the stool
• diarrhea
• weight loss
• fever

You may also just not feel well, also called malaise.

Symptoms often start gradually and build slowly over time. You may experience periods when your symptoms go away completely (aka remission) and periods when they return (aka relapse).

Treatment

Healthcare professionals have a variety of tools to help treat UC, depending on the severity and extent of the disease. Most people experience remission within 10 years of starting treatment.

Treatments often involve a combination of medications, lifestyle strategies, and, in some cases, surgery to remove all or part of the colon.

Common medications for UC include:

• aminosalicylates, which help with mild UC or when in remission
• immunosuppressants, which help with moderate to severe UC
• corticosteroids, which may be used in mild cases that don’t respond to aminosalicylates, or in cases of moderate to severe UC
• biologics, which are typically used for moderate to severe UC

Lifestyle changes may also improve your quality of life.

In a small 2020 study, researchers found making comprehensive lifestyle changes can significantly improve a person’s quality of life with UC.

Comprehensive lifestyle changes included:

• exercise, including yoga
• stress management
• mindfulness
• communication
• self-awareness
• cooking

Researchers trained participants to incorporate these changes into their daily routines.

You may also find support groups and mental health care helpful in managing the stress of living with UC. The Crohn’s and Colitis Foundation offers a support group finder.

A healthcare professional can also provide resources on local groups or mental health professionals in your area.

Microscopic colitis

Microscopic colitis is a less common form of IBD. It occurs due to an abnormal immune system response that causes inflammation in the large intestine.

Some medications can also increase your risk of developing microscopic colitis. These include:

• NSAIDs
• proton pump inhibitors
• selective serotonin reuptake inhibitors
• beta-blockers
• statins
• hormone replacement therapy

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

They have similar symptoms and treatments. They differ, however, in the changes they cause to the large intestine. In both types, the large intestine lining contains more white blood cells than normal.

But in collagenous colitis only, the collagen layer under the lining of the large intestine also becomes thickened.

Symptoms

Symptoms of both types of microscopic colitis are similar to other types of IBD.

The most common symptom is watery, non-bloody diarrhea.

Other symptoms can include:

• fecal incontinence
• diarrhea that occurs at night
• weight loss
• pain in the belly
• urgent need to have a bowel movement
• fatigue

Treatment

Treatment often involves taking new medications, stopping smoking, adjusting previous medications if they contributed to the colitis, and making changes to what you eat or drink. In rare cases, surgery may be needed.

Medications for microscopic colitis are similar to those used in UC and can include:

• corticosteroids
• biologics
• aminosalicylates
• antidiarrheal medications
• bile acid binders

Pseudomembranous colitis

Pseudomembranous colitis is a severe type of colitis. It most commonly arises from a Clostridioides difficile (C. diff) infection. Other types of infections can also cause this condition.

C. diff has increased in the past 20 years. As a result, the number of pseudomembranous colitis cases is also on the rise.

In pseudomembranous colitis, the lining of the colon is inflamed, and the colon develops yellow-white plaques that cling together to form pseudomembranes on the mucosa.

Symptoms

The most common symptom of pseudomembranous colitis is diarrhea.

Other symptoms can include:

• abdominal cramping
• fever
• high white blood cell count

In about 3% to 8% of cases, it can also lead to severe complications that can become life threatening. These include:

• toxic megacolon, which is swelling and inflammation in deeper layers of the colon
• severe ileus, or the inability for the intestines to push food through the digestive tract
• kidney dysfunction
• hypovolemia, or low volume of liquid in the body due to water and sodium loss
• hypotension, also called low blood pressure
• colonic perforation, which is development of a hole in the colon that can lead to inflammation and infection in the lining of the abdomen
• septic shock

Treatment

Doctors typically treat the C. diff infection that causes pseudomembranous colitis with antibiotics, such as:

• vancomycin
• fidaxomicin
• metronidazole

How well treatment works varies based on the severity of the C. diff infection. Mild infections typically resolve quickly with treatment.

If your condition is severe or recurrent, your doctor may recommend a procedure called a fecal microbiota transplant.

Ischemic colitis

The word “ischemia” refers to reduced or restricted blood flow in a certain part of the body. Ischemic colitis occurs when not enough blood flow reaches the large intestine (colon). This is often the result of atherosclerosis, though many other risk factors exist.

Though it can affect anyone, it is more common in females. It’s also more common in people in their 60s and 70s.

Symptoms

Like other types of colitis, ischemic colitis causes pain or tenderness in the belly. Other signs and symptoms include:

• abdominal cramping
• bloody bowel movements
• a high white blood cell count

It often starts suddenly and may be mild to severe.

Treatment

Ischemic colitis treatment depends on the severity of damage to the colon as well as the underlying cause.

Treatments may include:

• antibiotics to prevent or treat infections
• intravenous (IV) fluids
• angioplasty and stenting to help restore blood flow
• surgery for severe cases to help restore blood flow

Allergic colitis (allergic proctocolitis)

Allergic colitis is now known as allergic proctocolitis. It’s a food allergy that usually occurs in very early childhood. Symptoms may first appear when an infant is just a few weeks or months old. Less frequently, it can affect older children, up to age 14 years.

Allergic proctocolitis appears to be primarily related to proteins in cow’s milk, though allergies to corn, soy, eggs, and wheat can also trigger the condition.

It can affect both breastfed and formula-fed infants.

Symptoms

The main symptom is the appearance of bright red blood in the stool. It may occur with or without mucus. This appears in otherwise healthy babies.

Less frequently, an infant may have symptoms such as:

• belly pain
• refusal to eat
• pain during defecation
• irritability
• flatulence

Treatment

Treatment generally involves removing the triggering food from the diet. The outlook for children with this type of colitis is generally good. Most children are able to consume the trigger food by age 1 year.

The takeaway

Several types of colitis exist. They vary in their underlying causes, some of their symptoms, and their treatments.

If you experience belly pain, bloody diarrhea, or persistent diarrhea, you may want to discuss your symptoms with a healthcare professional. They can help investigate the underlying cause and help you find relief.