Colitis

Colitis is inflammation in your colon that can make your bowel movements urgent, painful, and sometimes bloody. While some types clear up quickly with treatment, others become chronic conditions requiring ongoing care and lifestyle changes.

Table of contents

• What is colitis?
• Associated anatomy
• Symptoms of colitis
• Causes and types of colitis
• Complications
• How doctors diagnose colitis
• Treatment
• Living with colitis

What is colitis?

Colitis is inflammation in your colon, which is the main part of your large intestine (the last part of your digestive system). Your colon is the last leg of the journey your food takes through your digestive system, where digested food becomes waste.^[1]

Inflammation makes the tissues in your colon swell and cause discomfort. This can affect the way the journey ends, causing pain, diarrhea and, sometimes, blood in your stool. Colitis can also affect your quality of life and make it difficult to do your normal activities.^[1]

There are different types of colitis. Some are short-lived and easy to treat, like when you have food poisoning. Other types are longer-lasting and difficult to treat. Colitis is more serious when it doesn’t go away. A severe case can damage your colon over time.^[1]

Associated anatomy

• Colon (large intestine)
• Rectum

Symptoms of colitis

Common symptoms of colitis include:^[1]

• Abdominal pain
• Bloating
• Feeling like you need to poop
• Watery diarrhea
• Mucus or blood in your poop
• Loss of appetite
• Fever
• Fatigue

People with colitis may experience blood or mucus in their stool and feel an urgent need to empty their bowels.^[3] Symptoms usually come in waves, and can range from mild to severe, depending on the amount of the colon affected and how badly the area is damaged.^[3]

Causes and types of colitis

The causes can vary depending on the type of colitis you have:^[1][4]

Infectious colitis is caused by a viral, parasitic or bacterial infection. Common causes include Salmonella, E. coli, Campylobacter jejuni, Shigella, and viruses such as cytomegalovirus. Most people get it from eating or drinking contaminated food or water.^[1][4]

Pseudomembranous colitis is the result of a specific bacterium known as C. diff (clostridioides difficile). C. diff already lives in your intestines, but certain antibiotics can cause C. diff to overgrow.^[1]

Allergic colitis primarily affects babies who drink breastmilk. An allergy to the protein in cow’s milk causes it.^[1]

Ischemic colitis is when your intestines aren’t getting enough blood. A blockage in your blood vessels, like a blood clot or atherosclerosis, causes it.^[1]

Inflammatory bowel diseases (IBD) are a group of conditions that cause chronic inflammation in your colon. They include ulcerative colitis, microscopic colitis and Crohn’s disease. Experts believe they’re a type of autoimmune disease, which means they cause your immune system to malfunction and attack its own tissue.^[1]

Radiation colitis is a side effect of radiation therapy, which is a treatment for certain types of cancer.^[1]

Diversion colitis is a side effect that can occur in people who’ve had a colostomy. Experts believe it happens when the part of your colon that’s not being used is deprived of certain nutrients.^[1]

Complications

Complications usually result from severe, long-term colitis. They can include:^[1][3]

Perforation: Chronic inflammation weakens your colon walls, making them more likely to rupture. An ulcer in your colon may wear a hole all the way through the lining of the colon. This can cause bacteria from your colon to infect your abdominal cavity or bloodstream.^[1]

Toxic megacolon: Severe inflammation causes the muscles in your colon to stop working. Food and gas build up in your colon and make it widen or stretch. This is a rare form of complication that requires urgent medical treatment.^[1][3]

Severe dehydration: This can result from the colon’s reduced ability to absorb water and from fluid loss during frequent trips to the bathroom.^[3]

Severe bleeding from the rectum: This can happen when ulcers cause a lot of blood to pass from the anus during a bowel movement.^[3]

Increased risk of colon cancer: Long-term inflammation in your colon can sometimes lead to changes in your colon wall that become cancerous.^[1]

How doctors diagnose colitis

Your healthcare provider will begin by asking you about your symptoms, when they began and what you were eating and drinking at the time. They’ll ask you about your current medications and any health conditions that you have. After a physical examination, they may recommend medical tests.^[1]

These are likely to include:^[1][6]

• Blood tests
• Stool tests
• Imaging tests to look at your colon

Endoscopic tests that check the inside of your colon with a lighted camera can be helpful in diagnosing the type of colitis you have. Colonoscopy and flexible sigmoidoscopy are common procedures used for diagnosis.^[1]

Sometimes a biopsy may be needed. This is a test of a sample of tissue from the intestine.^[6]

Treatment

Treatment of colitis depends on the etiology and severity of the condition.^[9]

Treatment based on type

For infectious colitis, treatment may include antibiotics or antivirals to eliminate the infectious agents. Most people with mild bacterial colitis recover without specific antibiotic treatment, though some bacterial infections like Shigellosis benefit from antimicrobial therapy.^[12]

For allergic colitis, treatment primarily involves dietary measures, such as diet adjustment and avoiding trigger foods.^[9]

For pseudomembranous colitis, treatment depends on the severity of disease. Mild cases require cessation of antibiotics and supportive therapy with fluids and electrolytes. Patients with severe or persistent disease should be treated with oral metronidazole or oral vancomycin.^[12]

Treatment for inflammatory bowel disease

For inflammatory bowel diseases, treatment aims to reduce symptoms during a flare-up and prevent symptoms from returning. In most people, this is achieved by taking medicine, such as:^[5]

• Aminosalicylates (ASAs)
• Corticosteroids (steroid medicines)
• Immunosuppressants

Mild to moderate flare-ups can usually be treated at home. But more severe flare-ups need to be treated in hospital.^[5]

Biologic medicines are medicines that reduce inflammation of the intestine by targeting proteins the immune system uses to stimulate inflammation. They may be used to treat moderate to severe disease if other options are not suitable or not working. These medicines are given in hospital as an infusion through a drip in your arm every 4 to 12 weeks, or as an injection.^[10]

Surgery

If medicines are not effective at controlling your symptoms or your quality of life is significantly affected by your condition, surgery to remove some or all of your bowel may be an option.^[5] Surgery can also be an option for treating the complications of colitis, such as bowel perforation or massive bleeding that cannot be controlled.^[9]

Living with colitis

Diet and nutrition

Most people with colitis are recommended to follow a healthy, balanced diet and drink plenty of fluids. This is to avoid dehydration and ensure you get all the nutrients you need.^[13]

Keeping a food diary that documents what you eat can be helpful. You may find you can tolerate some foods, while others make your symptoms worse. By keeping a record of what and when you eat, you should be able to identify problem foods and eliminate them from your diet.^[13]

Some people may be recommended to make temporary changes to their diet after surgery, or to help control symptoms during a flare-up. For example:^[13]

• Eating smaller meals more often, rather than 3 main meals
• Eating a low-fiber diet
• Taking food supplements

It’s important to speak to your care team before making any changes to your diet.^[13]

Stress management

Although stress does not cause colitis, successfully managing stress levels may reduce the frequency of symptoms. The following advice may help:^[13]

• Exercise – this has been proven to reduce stress and boost your mood
• Relaxation techniques – breathing exercises, meditation and yoga are good ways of teaching yourself to relax
• Communication – living with colitis can be frustrating and isolating; talking to others with the condition can help

Rest and self-care

When experiencing symptoms, it’s important to:^[6]

• Rest until you feel better
• When you feel like eating again, start with small amounts of food
• To prevent dehydration, drink plenty of fluids
• Take your medicines exactly as prescribed

Emotional support

Living with a long-term condition can have a significant emotional impact. In some cases, anxiety and stress caused by colitis can lead to depression. Signs of depression include feeling very down, hopeless and no longer taking pleasure in activities you used to enjoy.^[13]

It may be useful to talk to others affected by colitis, either face-to-face or via the internet. Support groups can provide helpful resources and connections with others who understand what you’re experiencing.^[13]