Colitis vs. Ulcerative Colitis: What’s the Difference?

Medically Reviewed by Minesh Khatri, MD on May 30, 2022
7 min read

Your belly hurts. The diarrhea keeps coming. And you certainly don’t feel like eating. These are telltale signs of colitis. But which kind?

Colitis is a term used to describe inflammation in your large intestine, or colon. There are many causes, including ulcerative colitis (UC). That’s a type of inflammatory bowel disease (IBD).

General colitis and ulcerative colitis can feel the same. You may not be able to tell them apart on your own. That’s where your doctor comes in. They have the tools to help you zero in on the right diagnosis and treatment plan.

Colitis can cause similar belly and bowel issues no matter the cause. Some symptoms are mild while others are more serious.

General signs of colitis and UC include:

You may also have:

If you have periods, you may have:

A key difference is what triggers colitis. For instance, IBD is usually an autoimmune issue. That’s when your immune system attacks healthy tissue in your body. Other kinds of colitis can be the result of outside factors, such as germs or medical treatments.

People with UC or other kinds of IBD may also have inflammatory symptoms alongside bowel problems, including:

But those aren’t the only distinctions. Here’s a breakdown by colitis type:

Ulcerative colitis (UC). This type of IBD causes sores (ulcers) and constant inflammation in the inner lining of your large intestine. UC often starts in the rectum and extends through the left side of your colon. But some people have colitis throughout most or all of their colon. That’s called extensive colitis or pancolitis.

Crohn’s colitis. This is a feature of Crohn’s disease, another type of IBD. Crohn’s can impact any part of your gastrointestinal (GI) tract — that’s your mouth to your anus. Unlike UC, you may have healthy tissue in between spots of inflammation. Crohn’s disease can also affect many layers of your GI tract.

Microscopic colitis. This is another type of IBD. It’s not related to ulcerative colitis or Crohn’s disease, but it’s associated with other autoimmune diseases. Like the name suggests, your doctor has to use a microscope to see any evidence of this kind of colitis.

There are two main forms:

  • Collagenous colitis occurs when a protein called collagen builds up in your colon.
  • Lymphocytic colitis is when a layer of white blood cells (lymphocytes) cause colon inflammation.

Some experts think collagenous and lymphocytic colitis may be different phases of the same condition.

Ischemic colitis. Sometimes your large intestine may not get enough blood. As a result, you can get sores (ulcers) in the lining of your colon. You may pass bright red blood clots even without pooping.

Experts can’t always find the cause of ischemic colitis. But it’s most likely to happen in people who:

  • Are 60 and older
  • Have heart and blood vessel disease
  • Have had surgery on a big blood vessel near the heart (aorta)
  • Have blood-clotting problems

Infectious colitis. Bacteria, viruses, and parasites can cause colitis. For example, E. coli is often the bacteria behind gut irritation that leads to traveler’s diarrhea. Infections are one of the main kinds of acute colitis. That refers to sudden bouts of inflammation that usually go away after a period of time.

Antibiotic-associated colitis. This is a type of infectious colitis. It’s sometimes called pseudomembranous colitis. It’s usually caused by an overgrowth of the bacteria Clostridium difficile. This can happen after you take antibiotics that kill off the microbes that usually keep “C. diff” in check.

Diversion colitis. You can get inflammation in parts of your colon after surgery for a stoma. That’s when a doctor creates a hole in your belly’s wall to act as an exit for your waste. According to scientists, a change in your gut bacteria may cause this kind of colitis.

Fulminant colitis. This is a rare but life-threatening complication of colitis. It causes the colon to get bigger. It happens most often in people who have ulcerative colitis or C. difficile-related colitis. But it can also happen with other forms.

Drug-induced colitis. Certain medications can irritate your colon or worsen IBD symptoms. Commonly, that includes nonsteroidal anti-inflammatory drugs (NSAIDs). But other medication can cause colitis, including drugs used to treat:

Go over any medication side effects with your doctor. Your colitis may go away when you stop certain drugs. But your doctor will let you know if it’s safe to make changes to your treatment plan.

Although it’s extremely rare, there have been cases of both collagenous and lymphocytic colitis developing into UC. Experts don’t know what caused these changes. But some think this means that these conditions could be points on a scale of inflammatory bowel disorders.

Your doctor will ask about the type and timing of your symptoms. They’ll probably feel your belly to see if it’s tender. Let them know about any medications that you take and if anyone in your family has ever had IBD or other digestive issues.

Everything you tell your doctor gives them clues about other tests you might need, such as:

Stool samples and bloodwork. Your poop and blood can reveal signs of infection or inflammation. Blood tests can also show low levels of iron. That’s called anemia. It can happen when colitis causes a lot of bleeding in your colon.

Imaging. Your doctor may take pictures inside your colon or rectum. They might use a special liquid called barium for some tests. That’s a substance that’ll coat your colon to help it show up better on X-rays.

You may also need:

Endoscopic tests. An endoscope is a camera attached to a thin, bendy tube. Your doctor can use it to look at your lower colon and rectum (sigmoidoscopy) or entire colon (colonoscopy).

Tissue biopsy. Your doctor may remove some tissue during a colonoscopy or sigmoidoscopy. A lab technician will use a microscope to check for signs of inflammation or other abnormal cells.

Your treatment depends on what’s causing your colitis. Here’s what might happen if you have the following:

Infection. You may or may not need medication to get rid of germs. In some cases, your doctor may tell you to stay hydrated while your body flushes out whatever bacteria, virus, or parasite is in your gut.

But you may also need:

If you have antibiotic-associated colitis, you’ll need to stop taking the medicine that led to your infection. Your doctor will give you a different antibiotic if you have an overgrowth of C. diff.

Inflammatory bowel disease (IBD). There isn’t a cure for UC or Crohn’s disease, but your doctor can help you manage your symptoms. You may need medication, diet and lifestyle changes, or surgery.

Ischemic colitis. You’ll likely need fluids through a vein in your arm. This’ll give your intestines a chance to rest and rehydrate. If there is a blood clot in an artery that leads to your intestines, thrombolysis may help. Your doctor will insert a catheter to deliver medication to break up the clot. If your blood flow doesn’t go back to normal, you may need surgery to take out parts of your colon.

Uncomfortable symptoms. Some kinds of colitis may go away on their own. But it can take time. Until you feel better, your doctor can help you manage issues like diarrhea and belly pain. The following may help:

  • Clear fluids for a day
  • Pain medication
  • Lots of rest

You may only need at-home or short-term care for some kinds of colitis. But UC is a condition you’ll have for the rest of your life. And it affects everyone in a different way. You’ll need to work with your doctor to find a treatment plan that works for you.

No matter what’s causing your symptoms, get medical care right away if you have:

  • Watery diarrhea for more than a few days
  • Heavy, ongoing diarrhea
  • Dark pee or little urination (a sign of dehydration)
  • Pain that doesn’t get better
  • A high fever