Lymphocytic colitis is one of the two main types of microscopic colitis. That’s colitis that’s only detectable under a microscope. It causes chronic inflammation in your colon, with a high density of inflammatory white blood cells called lymphocytes. That leads to chronic diarrhea.
Lymphocytic colitis is a type of microscopic colitis, which is a type of inflammatory bowel disease. Inflammatory bowel diseases are chronic diseases that cause ongoing inflammation in your intestines. Colitis means inflammation of the large intestine (colon). Microscopic colitis is colitis that can only be seen under a microscope. Scientists recognize the different types of microscopic colitis by analyzing the cells in your intestinal lining.
Lymphocytic colitis is characterized by an abnormally high density of lymphocytes in your intestinal lining. Lymphocytes are a type of white blood cell. When they show up in large numbers, it usually means your immune system has been activated to fight off an infection. That’s what inflammation usually means, too. With lymphocytic colitis, there’s no infection, but your body acts as though there is.
Most scientists believe so. They believe all inflammatory bowel diseases are. Autoimmune diseases cause chronic inflammation in different parts of your body in the absence of any infection. They happen when your immune system attacks your own body’s cells, apparently mistaking those cells for infectious agents. Autoimmune diseases may be partly determined by genes, and partly by environmental factors.
Lymphocytic colitis causes chronic inflammation in your colon, which is the end part of your GI (gastrointestinal) tract. This is the last leg of the journey your food takes through your digestive system, where food waste is gradually condensed into poop. Inflammation in your colon can interfere with this process. With lymphocytic colitis, the most typical result is chronic, watery diarrhea, between five and 10 times a day.
Frequent, urgent diarrhea can certainly affect your quality of life. Fortunately, most people only have periodic symptoms. While lymphocytic colitis is a lifelong condition, it can go into remission for long periods. When it does flare up, most people find it manageable with medication and diet. It’s not likely to cause serious or permanent damage to your colon, as other types of inflammatory bowel disease can.
It can affect anyone, but it becomes more common with age. It rarely affects children and most people are diagnosed after the age of 65. It’s about twice as common in women or people assigned female at birth (AFAB) as in men or people assigned male at birth (AMAB). It’s also more common in people who smoke tobacco, and these people tend to develop lymphocytic colitis earlier than others, by an average of 10 years.
Up to 40% of people with lymphocytic colitis also have another autoimmune disease, such as:
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Lymphocytic colitis changes the cellular composition of your large intestinal lining (mucosa). This causes frequent, watery diarrhea — typically between five and 10 times a day. About half of people report cramping and abdominal pain with it. Severe diarrhea can also lead to fecal incontinence — difficulty holding poop in — and it may cause dehydration, unintended weight loss or fatigue as side effects.
Some people also experience inflammatory symptoms in other parts of their bodies. This is typical with chronic inflammatory diseases. In fact, it’s fairly common for people to have more than one autoimmune disease diagnosis at a time. Common secondary symptoms in people with lymphocytic colitis include joint pain and stiffness (arthritis), eye inflammation (uveitis) and skin rashes (psoriasis).
Chronic inflammation in your colon causes cellular changes that lead to chronic diarrhea. But scientists aren’t sure why chronic inflammation develops in the absence of infection. Most believe that it involves a combination of factors. Some people may be genetically predisposed to develop it, like other autoimmune diseases. But in addition to that, some environmental stress factor probably triggers it.
Possible triggers include:
By definition, lymphocytic colitis can only be diagnosed from a tissue sample examined under a microscope. A gastroenterologist will take the tissue sample during a colonoscopy. In this procedure, they’ll examine the inside of your colon with a flexible instrument called a colonoscope. They’ll take multiple tissue samples (biopsy) through the colonoscope and send them to a lab for analysis.
If you have lymphocytic colitis, your colonoscopy will appear normal, but your biopsies will reveal inflammation with a high density of lymphocytes. If you have another condition, it’ll probably be visible during your colonoscopy. Your gastroenterologist will probably try to rule out other possible causes before testing you for microscopic colitis. They may order blood tests or poop tests first.
Some people improve with minimal treatment, and others require prescription medication. It may take some trial and error to determine what works best for you. Your doctor will make suggestions based on how severe your symptoms are and how you respond to conservative treatment. They may begin by suggesting changes to your existing medications and diet before prescribing new medications.
Medications may include:
Strictly speaking, it’s not curable because it can always come back. However, it can go into remission, which means the diarrhea and inflammation go away. Many people see their symptoms resolve almost completely over the course of a few years. In some people, remission appears to happen spontaneously. In others, it happens after figuring out the treatment, diet and lifestyle changes that work for them.
Your doctor may recommend that you avoid foods that commonly trigger diarrhea. You can test these foods individually if you’d like to see if they trigger yours. You may also have particular food sensitivities that aren’t on the list. Take notice of how your symptoms change when you add or remove certain foods. (An elimination diet, such as the Low-FODMAP diet, can help you isolate your food triggers.)
Common foods to avoid include:
For a severe flare-up of diarrhea, your doctor may recommend you fall back on the BRAT diet. BRAT stands for bananas, rice, apple sauce and toast. Basically, it means bland, easy-to-digest foods. This isn’t a nutritious long-term diet, but it’ll do for a few days. If you need a less restricted diet to manage your symptoms for longer periods, try a soft diet. It’s low-fat and low-fiber, but more varied and nutritious.
Collagenous colitis is the other main recognized type of microscopic colitis. Collagenous colitis is characterized by abnormally thick bands of connective tissue in your intestinal lining. Aside from their microscopic differences, collagenous colitis and lymphocytic colitis cause the same symptoms and are treated in the same way. Some believe they might actually be different stages of the same disease.
A note from Cleveland Clinic
Lymphocytic colitis is a chronic disease that develops relatively suddenly and late in life. It’s also somewhat obscure and not as well understood as other inflammatory bowel diseases. This can be a bewildering diagnosis to receive, especially if you’ve never heard of it before. But the good news is that it’s usually a manageable disease. With treatment and self-care, it can even go into remission.
Last reviewed by a Cleveland Clinic medical professional on 01/19/2023.
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