Intestinal Metaplasia

What is intestinal metaplasia?

Intestinal metaplasia is a transformation of the cells in the lining of your upper digestive tract, often the stomach or the esophagus (food pipe). It’s called “intestinal” metaplasia because the cells change to become more like those that line the intestines. When doctors find intestinal metaplasia, it looks like the mucosal lining of your esophagus or stomach has been replaced with intestinal lining. In the esophagus, this condition is also known as Barrett’s esophagus. In the stomach, it may be called gastric intestinal metaplasia.

Who does this condition affect?

Scientists believe metaplasia is a response to chronic irritation of cells. This irritation comes from a variety of environmental factors, including smoking and alcohol. Intestinal metaplasia in the esophagus (Barrett’s esophagus) could occur because of chronic acid reflux from your stomach into your esophagus. You may be more likely to have Barrett’s esophagus if you have a history of chronic acid reflux (GERD), smoking and/or drinking.

On the other hand, intestinal metaplasia in the stomach is associated with a widespread bacterial infection known as Helicobacter pylori, which can attack the protective mucous lining of the stomach. Another condition called “autoimmune metaplastic atrophic gastritis” can also lead to intestinal metaplasia of the stomach. In this condition, your own body’s immune system attacks the lining of your stomach. This condition is inherited.

How does this condition affect my body?

Intestinal metaplasia is usually asymptomatic, which means it doesn’t cause symptoms on its own. You may have symptoms related to the cause of the condition, such as chronic acid reflux or H. pylori infection, which cause you to seek medical care. Intestinal metaplasia is usually found during an examination, such as an upper endoscopy or a biopsy, looking for something else. However, in spite of causing no direct symptoms, it's a significant cellular change in your body and one that your healthcare provider will want to keep an eye on. It has the potential to progress into something more serious.

Is intestinal metaplasia serious?

This condition is considered a risk factor for cancer. It’s not cancer, but it’s a step toward it. Cells that have transformed once are more likely to transform again. If they go through another stage of transformation, known as dysplasia, they will become precancerous cells. The next stage after that will be cancer. Intestinal metaplasia may advance to stomach cancer or esophageal cancer over time in a small percentage of people. It’s still not very likely, but your healthcare provider will want to screen you regularly and take steps to prevent metaplasia from progressing if possible.

How is gastric intestinal metaplasia categorized?

Your healthcare provider may categorize gastric intestinal metaplasia (IM) based on the extent it's in your stomach:

• Focal means IM is limited to a small, localized area in your stomach.
• Extensive means IM is found in more than one area of your stomach. Extensive IM is more likely to progress toward cancer.

Your healthcare provider may also categorize gastric intestinal metaplasia based on the degree of cellular transformation:

• Complete IM, also called Type I means the new cells in your stomach most closely resemble the cells of the small intestine. This is considered the first stage of intestinal metaplasia.
• Incomplete or Type II IM means the new cells more closely resemble the cells of your large intestine (colon). This is considered an advanced stage of IM and is more likely to progress to dysplasia.
• Some scientists also define a Type III based on a slightly different configuration of cells. Type III would also fall under the category of incomplete IM.

What are the stages of intestinal metaplasia?

Low-grade dysplasia

In low-grade dysplasia, some cells are displaying the beginnings of architectural changes. These are considered precancerous cells, but they don’t appear to be changing aggressively. Your healthcare provider may recommend treating low-grade dysplasia before it progresses.

High-grade dysplasia

In high-grade dysplasia, the cells show more complex architectural changes, including branching and budding, but they don’t yet appear to be invasive. This is a step closer to cancer. Your healthcare provider may recommend treating high-grade dysplasia before it progresses.

How common is this condition?

Since intestinal metaplasia causes no direct symptoms and can only be diagnosed through testing, it’s impossible to know how common it is in the general population. Estimates range between 3% and 20% among all Americans. Gastric IM is more common among those of Hispanic and East Asian descent. Barrett’s esophagus is more common in white men.

What causes intestinal metaplasia?

Intestinal metaplasia seems to be caused by a reaction to prolonged irritation of the tissues lining the stomach or esophagus. Scientists don’t know exactly why it occurs in some people and not others, but it seems to involve a combination of factors, including:

• How many different irritants affect the tissues.
• How severe the irritants are.
• How long the tissues have been exposed to those irritants.
• Genetic predisposition (a family history of IM or of gastric or esophageal cancer).

What irritants contribute to intestinal metaplasia?

The primary culprits include:

• Gastric acid (and acid reflux).
• Bile salts (and bile reflux).
• H. pylori infection.
• Smoking.
• Alcohol.
• Environmental pollutants.

What prior conditions may advance to intestinal metaplasia?

You may be more at risk of developing IM if you have a history of:

• Esophagitis.
• Chronic gastritis or gastric atrophy.
• H. pylori infection.
• Acid reflux.
• Bile reflux.
• Alcoholism.

Are any other risk factors involved?

These additional risk factors increase your likelihood of developing intestinal metaplasia:

• High salt and fat consumption. Salt content is associated with gastric inflammation. Fat content increases bile salts in the digestive system, which may contribute to the breakdown of mucus when bile refluxes back into the stomach or esophagus.
• Low fruit and vegetable consumption. Fruits and vegetables are important for alkalizing your stomach and balancing acid content. They are also important sources of vitamin C and antioxidants, which have been shown to prevent IM.
• Age. Your risk of IM increases with age, simply because the condition has had more time to progress in older people.
• Genetics. Some people seem to be more genetically predisposed to develop IM.

What are the symptoms of intestinal metaplasia?

IM doesn’t cause symptoms on its own. But if you have IM, it means your stomach or esophagus has been exposed to chronic inflammation for a long time. You’re likely to have noticed those symptoms at times.

Inflammation in your esophagus (esophagitis) might feel like:

• Difficult or painful swallowing.
• Acid regurgitation (backflow into your mouth).
• Heartburn.

Inflammation of the stomach lining (gastritis) might feel like:

• Stomach pain.
• Bloated stomach.
• Nausea.

How is intestinal metaplasia diagnosed?

IM is often discovered by accident while screening for other conditions, usually during an upper endoscopy exam. During the exam, the endoscopist will see tongues of salmon-colored lining extending into your esophagus. In your stomach, IM looks like abnormal patches. The endoscopist will take a biopsy of the abnormal tissue to confirm their suspicion. If you have a history of chronic gastritis or acid reflux, your healthcare provider may order an upper endoscopy to check for IM.

What happens during an upper endoscopy exam?

Your healthcare provider will offer you medication before the exam to help you relax and numb your throat. Then they will pass a long, thin, flexible tube with a camera and a light at the tip, down your throat, through your esophagus, into your stomach and the first part of your small intestine (the duodenum). This tube is called an endoscope. The camera will display the insides of your upper digestive tract on a screen for your healthcare provider to examine. The whole process, including sedation, takes about 30 minutes.

How is intestinal metaplasia treated?

Healthcare providers treat the condition by attempting to eliminate the irritants that cause it. By these means, they hope to at least prevent metaplasia from progressing. Quitting smoking and drinking alcohol, treating acid reflux and eradicating H. pylori infection gives your tissues a chance to recover from the chronic inflammation that triggers metaplasia. If metaplasia progresses to dysplasia, healthcare providers may recommend removing the affected tissue to prevent it from progressing to cancer.

Can intestinal metaplasia be cured?

In theory, by catching it early enough and eliminating irritants completely, metaplasia could be reversible over time. However, studies have not conclusively shown this to be successful so far. The only known way to eliminate intestinal metaplasia is to remove the affected tissue. Even then, metaplasia sometimes reappears. This might be because it’s difficult to find all of the affected tissue to remove, or it might be because the programming of the cells has permanently changed. Long-term studies following treatment are needed to resolve this mystery.

How can I prevent or reduce my risk of developing intestinal metaplasia?

IM develops over a long period of chronic inflammation. You can significantly reduce your risk by working to reduce irritation to your stomach and esophagus over time by:

• Quitting smoking and/or drinking alcohol. Even reducing the frequency of your habit will help reduce the damage. If you are exposed to second-hand smoke in your home or workplace, consider ways to minimize your exposure.
• Taking your symptoms seriously. If you have swallowing or digestive problems, stomach pain or heartburn, or a known case of chronic acid reflux, take the trouble to seek treatment. Your healthcare provider can help you find ways to manage your condition.
• Getting regular checkups. It’s possible to have gastritis or esophagitis without noticing symptoms. Regular checkups with your healthcare provider can help ensure you are in good general health. The earlier these preconditions are caught and managed, the less likely they will be to progress.
• Maintaining a healthful diet. For all sorts of reasons, including IM, you can protect your health by eating a diet lower in fat and salt content and higher in fruits and vegetables.

What can I expect if I have this condition?

Your healthcare provider will want to keep it under observation. While most cases won’t progress all the way to cancer, you will want to intervene well before that. In the meantime, your healthcare provider will focus on treating the causes of IM. This will usually involve lifestyle changes for you.

How should I take care of myself?

Follow your healthcare provider’s guidance, including lifestyle changes and regular screenings to ensure IM doesn’t progress.

What questions should I ask my healthcare provider?

At your appointment, you can ask:

• If your IM is focal or extensive.
• If your IM is complete or incomplete.
• If your IM appears to be progressing or receding.
• What else can be done to manage your condition.

A note from Cleveland Clinic

Intestinal metaplasia of the stomach or esophagus is a sign of injury. It may or may not be reversible. While it might not cause symptoms on its own, it indicates that significant damage has already been done. It’s also a warning that more serious damage could result if the injury doesn’t stop. Even though the chance of cancer is small, it’s important to take this warning seriously and try to reduce or eliminate what's injuring your stomach or esophagus. Given the chance, partial or complete healing may be possible, and worse outcomes can be avoided.