Erythematous mucosa is a fancy term for redness in the soft tissue that lines the inside of your hollow organs. When healthcare providers use this term, they’re usually talking about organs in your GI tract. They might see red mucosa when they take a look inside your organs. It’s a sign of inflammation, which has many causes.
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Erythematous mucosa means the tissue that lines your gastrointestinal tract is red and irritated. This tissue is called mucosa. Redness is a sign of inflammation. This means something is bothering your GI tract. Your healthcare provider will tell you where they see the redness.
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Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy
Organs in your GI tract include your:
You might hear or read the term “erythematous mucosa” after having an exam inside one of these areas, especially if you’ve had pain, swelling or bleeding in your GI tract. These are symptoms of irritation. “Erythematous mucosa” is what it looks like.
Redness and swelling in your GI tract can happen for many reasons. Infections are some of the most common causes. But some issues only affect certain parts of your GI tract. Your exam report will tell you where your healthcare provider found erythematous mucosa.
Here are some common causes:
Irritation in your esophagus (esophagitis) is often related to long-term acid reflux (GERD). Stomach acid backs up and irritates the lining of your esophagus. Over time, this can cause ulcers or lead to other changes, like Barrett’s esophagus. Taking certain medications too often can also irritate the area.
A bacterial infection called H. pylori is often the cause of stomach lining inflammation (gastritis). It can wear down the lining and lead to stomach ulcers. Other common causes include drinking too much alcohol or overusing pain relievers like NSAIDs (nonsteroidal anti-inflammatory drugs).
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Redness and swelling in your small intestine (enteritis) are usually due to a short-term infection, like food poisoning or stomach flu. But when it lasts longer, it may be from a chronic condition like celiac disease or Crohn’s disease. These are both autoimmune diseases.
Your large intestine includes your colon, rectum and anus. Irritation in your colon (colitis) could be from an inflammatory bowel disease like ulcerative colitis. It could also be from a stubborn infection like C. diff, which can cause thick patches called pseudomembranes.
Inflammation in your rectum (proctitis) might be from a sexually transmitted infection (STI). In your anus, it could be due to a yeast infection. If you have chronic constipation, passing hard stools can cause sores or tears. If these get infected, they can cause a pocket of pus (abscess).
Less common causes of erythematous mucosa include:
Healthcare providers usually find erythematous mucosa during an exam of your GI tract called endoscopy.
Sometimes, healthcare providers can recognize what’s causing the redness just by looking. Other times, they’ll take a sample of the mucosa (biopsy) during the exam. A pathologist will study the sample under a microscope to help find the cause of the irritation.
Treatment depends on what’s causing the redness and swelling. Your healthcare provider will work to find the cause and then treat it. This should reduce the redness and may help with other symptoms.
For example, you might need:
If you’ve been anxiously awaiting the results of an endoscopy exam, seeing “erythematous mucosa” on your report might not make you feel better. But this term just means there’s redness inside your GI tract — a sign of inflammation. If you’ve had symptoms, this is one step closer to finding out what’s going on and how to treat it.
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If you have issues with your digestive system, you need a team of experts you can trust. Our gastroenterology specialists at Cleveland Clinic can help.
Last reviewed on 07/01/2025.
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