Colitis: Causes, Symptoms, & Treatment

By Chris Bodle, MD
Medically reviewed checkmarkMedically reviewed
March 1, 2020

The large intestine, or colon, is the end portion of your digestive system and stretches across most of your abdomen. Colitis is a general term describing conditions that involve inflammation of the colon. The most common form of colitis is ulcerative colitis, which affects 750,000 people in the United States and, if left untreated, can lead to life-threatening complications. Ulcerative colitis is the most common but there are also other types of colitis, including ischemic colitis, microscopic colitis, and infectious colitis.

What Is Colitis?

Colitis generally refers to inflammation in the inner lining of the colon. Colitis symptoms can range from mild to severe, and most commonly include persistent diarrhea or constipation, bloody stools, fatigue, and abdominal pain. These symptoms can be debilitating and cause extreme discomfort. If you have severe abdominal pain, bloody stools, or prolonged bouts of diarrhea, seek medical attention.

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Colitis is often caused by autoimmune diseases (when your immune system attacks healthy tissue), immune system reactions to infections, or inflammation caused by foreign substances, including medications. Some forms of colitis are also thought to be hereditary, meaning you are more likely to develop it if you have family members with the disease.

Types and Causes of Colitis

The most common types of colitis include:

Ulcerative colitis

Ulcerative colitis is an inflammatory bowel disease (IBD) that causes chronic inflammation of the colon. This is often an autoimmune disease, meaning your body’s own immune system attacks the lining of the colon. This inflammation can cause symptoms of abdominal pain, abdominal cramping, and diarrhea. The chronic inflammation can cause ulcerations in the lining of your colon and may even cause bleeding. If left untreated, ulcerative colitis symptoms can worsen and require long-term care and treatment. Individuals with ulcerative colitis also have an increased risk of developing colon cancer.

Ischemic colitis

Ischemic colitis is an inflammation of the colon caused by lack of blood flow to the large intestine. Pain from ischemic colitis can come on suddenly or gradually and it can feel like a sharp pain or stomach cramps. This tends to occur more frequently in older patients and patients with existing vascular disease (blood clots, artery narrowing, certain heart arrhythmias).

Microscopic colitis

Microscopic colitis is an inflammation of the colon visible only via microscope. There are many causes of microscopic colitis, including some medications, certain autoimmune diseases, like psoriasis, and even tobacco use.

Infectious colitis

There are several bacterial, viral and parasitic infections that can cause inflammation of the colon leading to diarrhea, fever, and abdominal pain. A common infection, Pseudomembranous colitis is caused by the Clostridioides difficile (C. diff) bacteria, which can cause abdominal pain, fever, and profuse amounts of diarrhea.

Symptoms of Colitis

The most common symptoms of colitis are abdominal pain and diarrhea, but symptoms vary depending on the type of colitis. Other symptoms can include:

  • Ulcerative colitis: Rectal or abdominal pain, fever, diarrhea accompanied by pus or blood, rectal bleeding, and fatigue.
  • Ischemic colitis: Diarrhea, nausea, vomiting, bloody stools. Typically severe abdominal pain that can be sharp or feeling like cramping.
  • Microscopic colitis: Abdominal pain or cramping, diarrhea.
  • Infectious colitis: Fever, abdominal pain or cramping, stools with mucus or pus.

Risk Factors and Complications of Colitis

Aside from producing unpleasant symptoms, colitis can also put you at risk for other diseases including the following:

  • Higher risk of colorectal cancer: Ulcerative colitis can increase your risk of developing colorectal cancer. After 10 years of having ulcerative colitis, the risk of getting colorectal cancer increases by 2%. After 20 years, it goes up by 8%, and after 30 years, the risk is 18%.
  • Bowel perforation: A bowel perforation happens when chronic inflammation impairs the strength of the intestinal wall, eventually leading to the formation of a hole. A hole in your intestine is very painful and is a medical emergency.
  • Toxic megacolon: Chronic inflammation of the colon can impair the ability of the muscles surrounding the colon to contract in the usual manner and can cause a blockage. Toxic megacolon is rare but can be life threatening. This can present with constipation, abdominal pain, and abdominal distension.
  • Intestinal bleeding: Ulcerations and breakdowns of the wall of the intestine can cause bleeding. While some bleeding can be expected in colitis, in rare instances this bleeding can be profuse and life threatening.

How Is Colitis Diagnosed?

To receive a diagnosis of colitis, you will want to visit your primary care doctor for a review of your medical history and a complete physical examination. You may then be referred to a gastroenterologist. To find a definite colitis diagnosis, the following methods may be used:

  • Stool sample testing
  • CT or MRI imaging
  • Barium enema: The colon is injected with barium, a white liquid, then an X-ray is taken. The barium coats the intestines, helping make the X-ray image clearer.
  • Colonoscopy: A long tube is inserted into the anus with a camera at one end, allowing the colon and rectum to be viewed in their entirety.

Colitis Treatment Options

Treatment options for colitis depend on the underlying cause. With most cases of colitis, treatment is focused on alleviating the symptoms. Initial treatment options typically consist of rest, over-the-counter pain relievers (i.e. Tylenol), and a 24-hour clear liquid diet. If the main symptoms of diarrhea and abdominal pain resolve, nothing further is needed. Patients should proceed with caution when using over the counter medicine to treat diarrhea. This is especially true if they have a fever or abdominal discomfort.

For those experiencing serious symptoms, more intense medical intervention may be needed, particularly in the following cases:

  • Ulcerative colitis: Treatment for ulcerative colitis can involve medication or surgery. Drug therapy can range from 5-aminosalicylic acid (5-ASA) to biologic medications. 5-ASA is an anti-inflammatory drug that is often the first treatment step for ulcerative colitis and includes olsalazine (Dipentum) and sulfasalazine (Azulfidine). Biologics are laboratory produced antibodies that help prevent certain proteins from causing inflammation. An example is golimumab (Simponi). As a last resort, surgery can be done to remove all or part of the colon.
  • Ischemic colitis: Ischemic colitis can be a medical emergency and requires going to the ER. Treatment may just require administering intravenous fluids. However surgery may be necessary if parts of the bowel have lost their blood supply.
  • Infection: Infections that cause colitis and diarrhea may require antibiotics. Certain bacterial infections will require antibiotics, while viral infections can resolve on their own with rest and plenty of fluids.

Prevention and What You Can Do at Home

Many patients with colitis have found that a proper diet can alleviate or mitigate symptoms. The Crohn’s & Colitis Foundation of American has the following dietary guidelines.

It’s recommended to avoid the following foods:

  • Lactose (sugar found in dairy items like milk and soft cheese)
  • Foods containing a lot of sugar, like juice and candy
  • Drinks containing caffeine or alcohol
  • Foods with a high fat content such as fried or greasy foods
  • High insoluble-fiber foods like whole nuts or raw green vegetables

Try these meal planning tips:

  • Utilize simple cooking methods, such as poaching or steaming
  • Avoid using a straw when drinking, as it can cause gas by making you ingest air
  • Consume four to six smaller meals each day
  • Keep yourself hydrated with liquids like water, broth, and tomato juice

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Other conditions may produce similar symptoms to colitis, including:

  • Crohn’s disease: Crohn’s disease is an autoimmune disease that causes chronic inflammation in the digestive tract. It mostly affects the small intestine and colon, but can affect any part of your GI tract. Crohn’s disease is similar to ulcerative colitis in that they are both types of inflammatory bowel disease (IBD), though ulcerative colitis can only be found in the large intestine. Ulcerative colitis cannot turn into Crohn’s disease.
  • Irritable bowel syndrome (IBS): IBS is a disorder of the large intestine that can cause symptoms similar to colitis. The main difference between ulcerative colitis and IBS is that ulcerative colitis produces visible signs of ulceration in the large intestine while IBS does not. There is no evidence that IBS can turn into colitis.
  • Diverticulitis: Diverticulitis is defined as the inflammation of diverticula, small outpouches that can form in your intestines. Symptoms include fever and intense abdominal pain, usually on the lower left side.

When to See a Doctor

You should see a doctor if you experience any symptoms of colitis, especially ulcerative colitis. Your primary care doctor or gastroenterologist will want to determine what is causing your abdominal pain and diarrhea or constipation.

If you’ve been diagnosed with colitis and any of the following symptoms are present, make an appointment to see your doctor:

  • Rashes of indeterminate cause
  • Pain in joints
  • Recurring stomach pain
  • Weight loss without explanation

How K Health Can Help

Are you experiencing symptoms that might be colitis? Use K Health’s virtual diagnosis tool to review your symptoms, or to chat with a K physician to better and learn more about what treatment options might be best for you.

Do you think you might have colitis?

Download the K Health app to learn more and chat with a doctor.

K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Chris Bodle, MD

Dr. Bodle is a board certified emergency medicine physician. He received his medical degree from Indiana University School of Medicine, and completed his residency in emergency medicine at Emory University. In addition to K Health, he currently works as an Emergency Medicine physician in an Urban, Level 1 Trauma Center in the south east.