What is lymphocytic colitis?

Lymphocytic colitis is inflammation of your large intestine. It causes episodes of watery diarrhea and belly pain.

Your large intestine is part of your digestive (gastrointestinal or GI) tract. It includes both the colon and rectum. It goes from your mouth all the way to your rectal opening. The large intestine receives the broken-down products of food from the small intestine. One of its main jobs is to reabsorb water and electrolytes, such as salt. The colon leads to the rectum, which stores your feces before your body expels them.

In lymphocytic colitis, inflammatory cells from your immune system travel to your large intestine. Here they cause swelling and inflammation of the tissues. In rare cases, these cells also invade the latter part of the small intestine. Immune cells (lymphocytes) may build up in the area as well. The inflammation may keep your large intestine from reabsorbing as much water as it should. This leads to diarrhea, belly pain, and other symptoms.

Lymphocytic colitis is one type of inflammatory bowel disease (IBD). IBD is a group of conditions that cause inflammation in either the small or large intestine. Lymphocytic colitis is a type of microscopic colitis. Microscopic colitis is inflammation of the large intestine that can only be seen through a microscope. The other main type of microscopic colitis is collagenous colitis. Some experts think lymphocytic colitis and collagenous colitis might be the same illness presented in different ways.

Lymphocytic colitis is not common. It’s more common in older adults. But it can affect younger adults and children. It’s also seen more in women than in men.

What causes lymphocytic colitis?

Experts are trying to understand what causes the inflammation of the large intestine that leads to lymphocytic colitis. Some people think that something in the GI tract triggers this abnormal immune response. This might be bacteria, pollen, or food.

Taking certain medicines may also trigger the condition in some people. These medicines can include:

• Nonsteroidal anti-inflammatory drugs (NSAIDs). These can include aspirin or ibuprofen.

• Acid reflux medicines

• High cholesterol medicines

• Diabetes medicines

• Medicines to treat depression

Certain bacteria may trigger lymphocytic colitis in some people. You might have your first episode after getting sick from bacteria. These can include Campylobacter jejuni or Clostridium difficile. Toxins in these bacteria may harm the inner surface of your large intestine. This can cause inflammation. Some experts think certain viruses may also play a role in lymphocytic colitis.

Experts don't think that food causes the condition. But certain foods may make lymphocytic colitis symptoms worse. These can include caffeine and milk products.  

Who is at risk for lymphocytic colitis?

Having certain health issues may increase your risk for the disease. These include:

• Diabetes

• Celiac disease

• Irritable bowel syndrome

• Certain types of thyroid disease

Being a smoker may increase your risk for the issue. Smoking interferes with the blood flow that your intestines need. Your risk for lymphocytic colitis may also be higher if someone in your family has the condition or another inflammatory bowel disease.

What are the symptoms of lymphocytic colitis?

The main symptom of lymphocytic colitis is chronic watery diarrhea. This diarrhea doesn't have blood. You may have several of these watery bowel movements each day. This may last for weeks or months. For most people, this diarrhea goes away for a while, but then it comes back later.

Other symptoms of lymphocytic colitis may include:

• Weight loss

• Belly pain

• Bloating

• Fluid loss (dehydration)

• Nausea

• Extreme tiredness (fatigue) or weakness

• Joint pain

• Not being able to control a bowel movement

How is lymphocytic colitis diagnosed?

You may need to see a gastroenterologist. This is a healthcare provider with special training to treat problems of the digestive tract.  

Your healthcare provider will ask you about your health history. They will also ask about your symptoms. Your healthcare provider will give you an exam, including an exam of your belly (abdomen).

Your healthcare provider will rule out other causes of your diarrhea. These can include an infection or another inflammatory bowel disease.

Your healthcare provider will also do other tests. These may include:

• Blood tests to check for anemia and infection

• Tests for celiac disease

• Stool analysis to check for inflammation or infection

You may also need a colonoscopy. This test looks at the lining of your colon and rectum. It uses a light and a tiny camera.

The colon often looks normal on a colonoscopy. During the colonoscopy, your healthcare provider can take out a small tissue sample of your colon. This is called a biopsy. The biopsy will be examined under a microscope in a lab to determine if you have lymphocytic colitis.

How is lymphocytic colitis treated?

Your healthcare provider may prescribe medicines and suggest diet changes to treat your condition.

What are possible complications of lymphocytic colitis?

Unlike other forms of inflammatory bowel disease, lymphocytic colitis doesn’t seem to increase your risk for colon cancer. It doesn't increase your risk of death from any cause.

When should I call my healthcare provider?

Call your healthcare provider if your symptoms don’t go away with treatment. Your provider may change your treatment plan.

Key points about lymphocytic colitis

• Lymphocytic colitis is a condition that affects your large intestine. It leads to episodes of watery diarrhea and belly pain.

• Bacterial and viral infections, certain medicines, or certain foods may trigger lymphocytic colitis in some people.

• Symptoms of lymphocytic colitis include watery diarrhea, belly pain, and fatigue.

• You may have a colonoscopy to diagnose this condition. During this test, your healthcare provider may take out a small tissue sample of your large intestine and send it to a lab for testing.

• You may need to take medicines to treat your condition. You may also need to stay away from certain foods and medicines that trigger your symptoms.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your provider tells you.

• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is advised and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your provider if you have questions.