What Is Erythema in the Stomach? Causes, Symptoms & Treatment

Erythema in the stomach is redness of the gastric lining, almost always spotted during an upper endoscopy rather than felt by the patient. It is a visual sign of inflammation, irritation, or increased blood flow in the mucosa, and it shows up on endoscopy reports with striking regularity. The redness itself is not a diagnosis but a finding that points toward an underlying cause, which can range from a common bacterial infection to bile washing backward from the small intestine. What matters is why it is there and whether it needs treatment.

What Erythema in the Stomach Actually Looks Like

During an upper endoscopy, the gastroenterologist passes a thin camera down your throat and into the stomach. Healthy gastric mucosa has a smooth, pale-pink appearance. When the lining is inflamed, it turns red, sometimes in patches, sometimes across broad swaths. The medical term for that redness is erythema, and it is the single most common abnormal finding on gastric endoscopy. It can appear anywhere in the stomach but tends to cluster in the antrum, the lower portion near the exit to the small intestine.

The endoscopy report will often describe the pattern: “diffuse erythema,” meaning widespread redness; “patchy erythema,” meaning scattered red spots; or “streaky erythema,” meaning lines of redness. These patterns are not just descriptive flourishes. Different distributions correlate with different causes, and trained endoscopists use standardized scoring systems to grade what they see. One widely used framework, the Kyoto classification, links specific endoscopic appearances to the type and severity of underlying inflammation in the stomach wall.¹

The Main Causes of Gastric Erythema

Helicobacter pylori Infection

H. pylori is probably the most important cause worldwide. This bacterium colonizes the stomach lining and triggers chronic inflammation. When the infection is active, the endoscope typically reveals diffuse mucosal erythema along with other telltale signs such as mucosal swelling, sticky mucus, and sometimes small nodules dotting the surface.² The redness reflects the body’s immune response: white blood cells flood the mucosa, blood vessels dilate, and the tissue becomes inflamed. Over time, if the infection goes untreated, the mucosa can progress from simple redness to atrophy and intestinal metaplasia, a precancerous change in which stomach cells start to resemble intestinal cells.

Bile Reflux

Bile is produced by the liver and normally flows from the gallbladder into the small intestine. In some people, bile washes backward into the stomach, a condition known as bile reflux gastropathy. The bile salts irritate and damage the gastric lining, producing erythema that is often described as moderate to severe, sometimes with a yellowish staining visible on the mucosa. In one study comparing patients with bile reflux gastropathy to those without, about 89% of the bile reflux group had gastric erythema compared with roughly 64% of those without bile reflux.³ The redness from bile reflux concentrates in the antrum and body of the stomach, much like H. pylori, which is one reason telling the two apart requires more than just looking at the color.

Autoimmune Gastritis

In autoimmune gastritis, the immune system attacks the acid-producing cells in the upper part of the stomach (the fundus and body). Early on, before significant tissue loss has occurred, endoscopy can show a mosaic-like pattern with slight swelling, diffuse redness, and edema of the mucosa in the fundic gland region. Small pseudopolyp-like nodules sometimes appear as well.⁴ Because autoimmune gastritis can quietly progress for years before causing obvious atrophy or anemia, recognizing these early endoscopic signs matters.

Smoking, Alcohol, and Other Irritants

Chronic use of NSAIDs (like ibuprofen or aspirin), heavy alcohol intake, and smoking can all irritate the gastric lining. In a study of over 360 patients, current smokers showed a trend toward more severe gastric lesions, with about 53% having clinically significant findings compared with roughly 44% of non-smokers or former smokers.⁵ Animal research has shown that cigarette smoke amplifies alcohol-induced stomach damage by reducing protective prostaglandins in the mucosa and ramping up inflammatory enzyme activity.⁶ In practical terms, if you drink and smoke, the combination is harder on your stomach than either habit alone.

Stress-Related Mucosal Disease

This one is not about everyday psychological stress. Stress-related mucosal disease occurs in critically ill patients, those in intensive care with major injuries, sepsis, organ failure, or other severe physiologic insults. Within 24 hours of ICU admission, the vast majority of critically ill patients develop some evidence of mucosal damage, ranging from erythema to erosions and frank ulceration.⁷ The driving forces are reduced blood flow to the stomach lining and impaired mucosal defenses rather than excess acid production.⁸ Recent animal work has added detail to this picture, finding that disrupted signaling between the vagus nerve and sympathetic nerves contributes to rapid mucosal injury after events like brain hemorrhage.⁹

Symptoms That May Accompany Gastric Erythema

Here is the frustrating part: erythema in the stomach often produces no symptoms at all. Many people only learn about it because they had an endoscopy for unrelated reasons or as part of a screening program. When symptoms do occur, they tend to fall under the umbrella of dyspepsia, a catch-all for upper abdominal discomfort. Common complaints include:

Burning or gnawing pain: usually in the upper abdomen, sometimes mistaken for heartburn.
Nausea: especially after meals or in the morning before eating.
Early fullness: feeling stuffed after eating only a small amount.
Bloating: a sense of pressure or distension in the upper abdomen.
Loss of appetite: which can be subtle or pronounced depending on severity.

The trouble is that the severity of erythema on endoscopy does not neatly predict how bad someone feels. Studies in diabetic patients, for instance, have found no significant difference in dyspepsia symptom scores between those with and without endoscopic abnormalities.¹⁰ A stomach can look angry and red but feel fine, or look relatively normal and be the source of persistent discomfort. This disconnect between appearance and symptoms is one of the enduring puzzles in gastroenterology.

What Specific Erythema Patterns Can Tell Your Doctor

Not all redness is equal. Endoscopists pay attention to the pattern, distribution, and texture of erythema because these visual clues can narrow down the diagnosis before biopsy results come back.

One pattern that has drawn particular research interest is mottled patchy erythema, an irregular, uneven redness that gives the mucosa a blotchy appearance. This pattern has a strong association with intestinal metaplasia, the precancerous tissue change mentioned earlier. In a study that systematically biopsied areas of mottled patchy erythema alongside normal-appearing mucosa in the same stomachs, about 87% of the blotchy red areas showed intestinal metaplasia under the microscope, compared with only about 33% of the non-erythematous sites. The pattern detected intestinal metaplasia with a sensitivity of roughly 73% and a specificity of about 84%.¹¹ In other words, when an endoscopist sees that blotchy red pattern, it is a fairly reliable signal that the tissue underneath has undergone worrisome changes and deserves targeted biopsies.

Diffuse erythema spread evenly across the mucosa, by contrast, more commonly reflects active inflammation from H. pylori or chemical irritation. Streaky linear redness concentrated in the antrum can suggest gastric antral vascular ectasia, sometimes called “watermelon stomach” because the red streaks resemble the stripes on a watermelon rind. Getting the pattern right steers the doctor toward the correct workup and, eventually, the right treatment.

Conditions That Mimic Each Other

Two conditions deserve special mention because they both produce prominent redness in the stomach and are frequently confused, yet their treatments are completely different. Gastric antral vascular ectasia (GAVE) involves dilated blood vessels that form the distinctive red stripes or spots in the antrum. Portal hypertensive gastropathy (PHG) occurs when elevated pressure in the portal vein system, usually from liver disease, causes congestion and redness across a broader area of the stomach.

Both can cause chronic, slow blood loss and iron-deficiency anemia. Both look red on endoscopy. But PHG responds to treatments that lower portal pressure, such as medications or procedures that reduce the venous load on the liver, while GAVE typically needs direct treatment of the abnormal blood vessels through endoscopic ablation or cauterization.¹² Mixing up the two can lead to treatments that do not work or, worse, delay the right intervention.¹³ When the endoscopic picture is unclear, biopsies help sort things out: the microscopic findings in GAVE and PHG differ enough to tell them apart in most cases.

How Gastric Erythema Is Treated

Because erythema is a sign rather than a disease, treatment targets whatever is causing the redness. The approach varies quite a bit depending on the diagnosis.

H. pylori Eradication

If testing confirms an active H. pylori infection, the standard approach is a course of antibiotics combined with an acid-suppressing drug, usually taken for 10 to 14 days. Clearing the infection leads to dramatic recovery of the gastric mucosa, with inflammation fading and mucosal function gradually returning toward normal.¹⁴ The redness visible on endoscopy typically resolves over weeks to months after successful eradication, though more advanced changes like atrophy and intestinal metaplasia may persist or only partially reverse. This is one reason catching and treating H. pylori earlier rather than later makes a difference.

Acid Suppression

For erythema related to chemical irritation, bile reflux, or non-H. pylori gastritis, acid-suppressing medications form the backbone of treatment. Proton pump inhibitors (PPIs) like omeprazole and lansoprazole reduce stomach acid production and promote mucosal healing. A newer class of acid suppressors called potassium-competitive acid blockers (P-CABs) has shown strong results in clinical trials, with some evidence of faster symptom resolution than traditional PPIs.¹⁵ These medications are generally taken for four to eight weeks, though some patients with chronic causes need longer courses.

Removing the Irritant

When erythema stems from an identifiable irritant, the most effective treatment is removing or reducing it. If NSAIDs are the culprit, switching to a different pain management strategy or adding a protective medication like misoprostol can help. For alcohol-related gastric irritation, reducing intake or stopping altogether allows the mucosa to heal. Smoking cessation removes a factor that not only causes direct mucosal damage but also amplifies the harm from other irritants and slows healing.

Managing Bile Reflux

Bile reflux is trickier to treat than acid reflux because PPIs do not neutralize bile. Sucralfate, which coats the stomach lining, and bile acid binders like cholestyramine are sometimes used. In severe or refractory cases, surgery to divert bile flow away from the stomach may be considered, though this is uncommon.

Stress Ulcer Prevention in the ICU

For critically ill patients, the approach is preventive. Most ICU patients receive acid-suppressing medication as a prophylactic measure to reduce the risk of stress-related mucosal damage progressing to bleeding. The standard choice is an intravenous PPI or an H2 receptor blocker started at admission, since mucosal damage can develop within hours of a severe physiologic insult.

When Erythema Alone Does Not Require Treatment

It is worth understanding that mild erythema noted incidentally during an endoscopy does not always demand treatment. If you had an endoscopy for reflux symptoms and the report mentions “mild erythema in the antrum” with biopsies that came back normal, and you tested negative for H. pylori, the finding may be clinically insignificant. Minor redness can result from the endoscope itself rubbing the mucosa, from recent food, or from a passing irritant that has already resolved. In these situations, your doctor might recommend no specific treatment beyond general advice about diet and avoiding known irritants.

The line between “incidental finding” and “something that needs attention” is drawn by the biopsy results, the H. pylori status, and the clinical context. If biopsies show active inflammation, intestinal metaplasia, or another specific abnormality, treatment and follow-up become important. If the biopsies are bland, the erythema is less concerning.

Autoimmune Gastritis and the Long Game

Autoimmune gastritis is worth singling out because it behaves differently from the other causes. The erythema and swelling seen early on are just the opening act. Over years, the immune attack progressively destroys the acid-producing parietal cells, leading to reduced stomach acid, impaired absorption of vitamin B12 and iron, and eventually pernicious anemia. Because the early endoscopic signs can be subtle, a mosaic-like mucosal pattern and diffuse fundic redness rather than the obvious ulcers or erosions that prompt urgent workups, autoimmune gastritis is frequently diagnosed late.⁴

Treatment focuses on monitoring and supplementation. There is no approved therapy to stop the autoimmune process itself, so management centers on replacing what the damaged stomach can no longer absorb: B12 injections, iron supplementation, and periodic endoscopic surveillance to watch for progression to gastric neuroendocrine tumors or gastric cancer, both of which carry elevated risk in this population. If you are told you have autoimmune gastritis, the erythema on your endoscopy report is a signpost for a condition that needs long-term follow-up rather than a one-time fix.

How Intestinal Metaplasia Changes the Conversation

When erythema in the stomach is associated with intestinal metaplasia on biopsy, the conversation shifts from simple inflammation management to cancer surveillance. Intestinal metaplasia is considered a precancerous condition because it reflects chronic damage that has altered the type of cells lining the stomach. Not everyone with intestinal metaplasia develops gastric cancer; in fact, the vast majority do not. But the risk is elevated enough that most guidelines recommend periodic surveillance endoscopies, with the interval depending on the extent and severity of the metaplasia and whether other risk factors like a family history of gastric cancer are present.

The mottled patchy erythema pattern discussed earlier is particularly useful here because it allows endoscopists to target their biopsies to the areas most likely to harbor metaplasia, improving detection rates compared with random sampling.¹¹ If you have intestinal metaplasia, eradicating H. pylori (if present) is strongly recommended because it can slow or halt further progression. Beyond that, the follow-up schedule and whether additional interventions are warranted depend on individual risk factors and should be worked out with a gastroenterologist.

1
PubMed Central. Consistency between the endoscopic Kyoto classification and pathological updated Sydney system for gastritis: A cross‐sectional study
2
The Korean Journal of Medicine. Endoscopic Features According to Helicobacter pylori Infection Status
3
PubMed Central. Bile Reflux Gastropathy and Functional Dyspepsia
4
PubMed Central. Endoscopic Features of Autoimmune Gastritis: Focus on Typical Images and Early Images
5
PubMed Central. Risk Factors for Endoscopic Gastric Mucosal Lesions: Analysis of Lifestyle, Dietary, and Clinical Determinants in 361 Patients
6
PubMed. The potentiating actions of cigarette smoking on ethanol-induced gastric mucosal damage in rats
7
PubMed. Pathophysiology of the upper gastrointestinal tract in the critically ill patient: rationale for the therapeutic benefits of acid suppression
8
PubMed. Prevention and treatment of stress ulcers in critically ill patients
9
PubMed Central. Dysregulated sympathovagal interplay contributes to gastric mucosal injury following subarachnoid hemorrhage
10
Medical Science and Discovery. Correlation of dyspeptic symptoms and endoscopic findings in diabetic patient
11
PubMed Central. Predictability of Gastric Intestinal Metaplasia by Mottled Patchy Erythema Seen on Endoscopy
12
PubMed Central. Comparison of portal hypertensive gastropathy and gastric antral vascular ectasia: an update
13
Journal of Education, Health and Sport. Gastric antral vascular ectasia, also known as watermelon stomach – diagnosis and treatment
14
PubMed Central. Helicobacter pylori eradication: Exploring its impacts on the gastric mucosa
15
Gut and Liver. Pharmacological Treatment of Gastritis: A Narrative Review with a Systematic Literature Search