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Understanding Colitis 

Colitis is when a part of your colon becomes inflamed or swollen. The colon is also called the large intestine. It helps with digestion and waste removal. 

What causes colitis?

Colitis can be caused by many things. The most common causes are:

  • Viral or bacterial infections

  • Inflammatory bowel disease (ulcerative colitis or Crohn’s disease)

  • Certain medicines, such as antibiotics

  • Radiation therapy to the colon

Symptoms of colitis

The symptoms of colitis may last a short time. Or they can be chronic. The most common symptoms are:

  • Diarrhea, sometimes bloody

  • Stomach pain or cramping

  • Fever

  • Weight loss in severe cases 

Diagnosing colitis

Your healthcare provider will take a full health history and family history. He or she will also give you a physical exam. Depending on the results of your history and physical exam, your provider may also order certain tests to help find out the cause of your colitis. These may include:

  • Lab tests. Your blood and stool will be checked.

  • Endoscopy and biopsy.  Endoscopy uses a long, flexible tube with a tiny light and camera on one end to check the inside of your large intestine. When only the colon is checked, this is called a colonoscopy. During an endoscopy, your provider may take a small sample of your tissue to look at under a microscope. This is called a biopsy.

  • Imaging tests. These include X-ray, CT scan, MRI, and capsule endoscopy.

Treatment for colitis

Treatment for colitis depends on what is causing it and how serious your symptoms are. In some cases, you may not need treatment. For example, colitis from an infection may go away without care. 

Treatment may include: 

  • Medicines. You may take these by mouth (oral) or  as a rectal suppository or enema. Some medicines are given by injection. They can lessen swelling and ease symptoms.

  • Changes in your diet. Some foods can make symptoms worse. Common triggers are milk, coffee, alcohol, and fried foods.

  • Surgery. In some cases, you may need surgery to remove a damaged part of the colon.

Call 911

Call 911 if any of these occur:

  • Trouble breathing

  • Confusion

  • Very drowsy or trouble awakening

  • Fainting or loss of consciousness

  • Rapid heart rate

  • Chest pain

When to call your healthcare provider 

Call your healthcare provider right away if you have any of these:

  • Symptoms that don’t get better, or get worse

  • Fever of 100.4°F (38°C) or higher, or as directed by your healthcare provider

  • Pain that gets worse

  • Bloody diarrhea

  • Bleeding from your rectum

  • New symptoms


Online Medical Reviewer: Jen Lehrer MD
Online Medical Reviewer: John Hanrahan MD
Online Medical Reviewer: Raymond Kent Turley BSN MSN RN
Date Last Reviewed: 4/1/2020
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