Stomach Ulcer: Causes, Testing and Treatment

Until the 1980s, stomach ulcers were understood as a disease of stress, personality and acid. Patients were told to relax, drink milk and avoid spicy food, and many spent decades with a condition that relapsed endlessly because nobody was treating the cause.

Then two Australian researchers proposed that a bacterium was responsible, were widely disbelieved, and one of them drank a flask of the organism to prove the point — developing gastritis and then curing himself with antibiotics. They received the Nobel Prize in 2005, and peptic ulcer disease went from a lifelong condition to a curable infection.

That history matters because the old advice persists. This guide covers what actually causes ulcers, how they are diagnosed, which treatments eradicate the infection, and which widely repeated recommendations have no evidence behind them.

🔬 What an ulcer actually is

The stomach produces hydrochloric acid strong enough to damage most tissue, and protects itself with a mucus layer, bicarbonate secretion, rapid cell renewal and a rich blood supply. An ulcer forms where that defence fails and acid and pepsin erode through the lining into deeper layers.

The distinction from gastritis is one of depth. Gastritis is inflammation of the surface; an ulcer is a defined break penetrating beneath it. Ulcers occur in the stomach itself, where they are called gastric, and in the first part of the small intestine, where they are called duodenal. Duodenal ulcers are commoner, more strongly associated with H. pylori, and almost never malignant. Gastric ulcers occur at older ages and can occasionally represent a cancer, which is why they are biopsied and followed up in a way duodenal ulcers are not.

🦠 What causes them

H. pylori is remarkably widespread — carried by a large share of the world population, acquired usually in childhood, and transmitted through close contact and contaminated water. The great majority of carriers never develop an ulcer. What determines who does involves bacterial strain, host genetics and the pattern of inflammation produced.

❌ What does not cause them

The persistence of these beliefs actively harms people, by directing effort toward dietary restriction and away from testing.

Everyday stress does not cause ulcers. Psychological stress may worsen symptoms and influence health behaviours, but it does not produce the lesion. The stress ulcers of medical literature occur in intensive care units following major physiological insult, which is a different phenomenon entirely.

Spicy food does not cause ulcers. Chilli can irritate an existing ulcer and produce symptoms, and there is some evidence that capsaicin is mildly protective. Avoiding it may be comfortable; it is not treatment.

Personality type does not cause ulcers. The idea of the driven, anxious ulcer patient was a mid-century construction that survived because it felt plausible.

Milk does not help. It buffers acid briefly and then stimulates further acid secretion, so it makes matters worse over a few hours. Drinking milk for ulcer pain was standard advice for decades and was actively counterproductive.

Acidic food does not cause ulcers. Stomach acid is far stronger than anything in a lemon.

🩹 How they present

The classic symptom is a burning or gnawing pain in the upper abdomen. Its relationship to food is somewhat characteristic: duodenal ulcer pain often improves with eating and returns two to three hours later, sometimes waking the person at night, while gastric ulcer pain frequently worsens with eating. Neither pattern is reliable enough to diagnose on.

Bloating, nausea, early fullness, belching, heartburn and reduced appetite accompany it. Weight loss occurs and should never be dismissed.

🔴 Complications and warning signs

Three complications account for the seriousness of the condition.

Bleeding is the commonest. It presents as vomiting blood or material resembling coffee grounds, or as black tarry stools with a distinctive smell. It can also be slow and hidden, causing iron deficiency anaemia with fatigue and breathlessness and no digestive symptoms at all.

Perforation is a surgical emergency: sudden severe abdominal pain, a rigid board-like abdomen, and rapid deterioration as stomach contents enter the abdominal cavity.

Obstruction follows scarring at the stomach outlet, producing persistent vomiting of undigested food, fullness and weight loss.

🧪 Diagnosis

Endoscopy visualises the ulcer directly, allows biopsy, permits treatment of bleeding, and tests for H. pylori at the same time. It is indicated where warning signs are present, in older patients with new symptoms, and to confirm healing of gastric ulcers, since a small proportion are malignant.

Non-invasive H. pylori testing suits younger patients without warning signs. The urea breath test and the stool antigen test both detect active infection and are used for diagnosis and to confirm cure. Blood antibody tests are far less useful, because antibodies persist after the infection has cleared and a positive result cannot distinguish current from past infection.

💊 Acid suppression

Proton pump inhibitors are the mainstay. They block the enzyme pump that secretes acid, reducing production far more effectively than earlier drug classes, and they heal the great majority of ulcers within four to eight weeks.

Timing determines whether they work properly: take a proton pump inhibitor thirty to sixty minutes before a meal, because the drug only inhibits pumps that are actively secreting. Taken on an empty stomach at bedtime it works considerably less well, and this single point explains a substantial share of apparent treatment failures.

H2 blockers such as famotidine reduce acid less powerfully but act faster, and are useful for breakthrough symptoms and at night. Sucralfate works differently, forming a physical protective barrier over the ulcer surface, and is taken away from other medicines because it interferes with their absorption.

🧫 Eradicating the infection

Where H. pylori is present, eradicating it is what turns a recurring condition into a resolved one. Recurrence after successful eradication is uncommon.

Treatment combines a proton pump inhibitor with two or three antimicrobials for ten to fourteen days. The specific combination has shifted over the past decade because of resistance, and this is the key modern point.

Two points about these regimens matter practically. The full course must be completed, because partial treatment selects for resistant organisms and makes the next attempt harder. And azithromycin is not part of any standard regimen — despite being a macrolide like clarithromycin, it performs poorly against H. pylori and should not be substituted.

Side effects are common: metallic taste, nausea, diarrhoea and darkened stools with bismuth, which is harmless. Alcohol must be avoided with metronidazole. Discomfort during the course is expected and is not a reason to stop early.

✅ Confirming it worked

This step is skipped constantly and it should not be.

Eradication is confirmed with a urea breath test or stool antigen test at least four weeks after finishing antibiotics and two weeks after stopping the proton pump inhibitor. Testing earlier produces false negatives and creates false reassurance.

Confirmation matters because first-line therapy fails in a meaningful proportion of cases, and an untreated persisting infection continues to cause ulcers and continues to carry the long-term risk of gastric cancer. Where the first attempt fails, a second regimen using different antibiotics is used, guided by sensitivity testing where available.

💉 Ulcers caused by painkillers

NSAID-related ulcers are managed differently, and the growing share of ulcers they represent reflects an ageing population on long-term anti-inflammatory and antiplatelet drugs.

Stopping the drug is the first step where possible, alongside a proton pump inhibitor. Where it cannot be stopped — low-dose aspirin after a cardiac event, for instance — the ulcer is healed while continuing it under acid suppression.

Prevention is the more valuable intervention. People needing long-term NSAIDs who have additional risk factors should be co-prescribed a proton pump inhibitor. Risk factors include age over sixty-five, previous ulcer or bleeding, concurrent aspirin, anticoagulants, corticosteroids or SSRIs, and higher NSAID doses.

Misoprostol replaces the prostaglandins that NSAIDs suppress and prevents ulcers effectively, though diarrhoea limits its use, and it must never be taken in pregnancy because it causes uterine contractions.

Anyone taking regular anti-inflammatory drugs should also know that H. pylori and NSAIDs together multiply risk, which is why testing before starting long-term NSAID treatment is recommended in people with a history of ulcer disease.

⏳ Long-term acid suppression

Proton pump inhibitors are among the most prescribed drugs in the world, frequently continued for years without review, and questions about long-term safety deserve a measured answer rather than either dismissal or alarm.

Observational studies have linked prolonged use with fractures, kidney disease, low magnesium, vitamin B12 deficiency, certain intestinal infections and pneumonia. Most of these associations are modest, and studies of this design struggle to separate the effect of the drug from the effect of the conditions that led to it being prescribed. Randomised evidence has been considerably more reassuring.

The sensible position is that these drugs are genuinely valuable where indicated — healing ulcers, preventing NSAID-related bleeding, treating erosive reflux — and should be reviewed periodically rather than continued indefinitely by default. Where the reason for starting has resolved, stepping down to the lowest effective dose or stopping is appropriate, with an awareness that rebound acid secretion can cause a temporary worsening for a couple of weeks after stopping, which is not evidence that the drug is still needed.

🍽️ Diet, realistically

Elaborate ulcer diets were built on a theory of the disease that turned out to be wrong, and most of their restrictions have no supporting evidence.

Raw vegetables, fruit, nuts and mushrooms do not need to be avoided. Bland diets do not speed healing. Frequent small meals do not confer benefit and were originally recommended on reasoning that no longer applies.

What is supported is narrower and worth doing:

• Stop smoking — it impairs healing, raises recurrence and increases complication risk. This is the dietary and lifestyle measure that actually matters
• Limit alcohol, which irritates the mucosa directly
• Avoid individual foods that reliably cause you symptoms, which varies between people and is about comfort rather than healing
• Do not lie down soon after eating if reflux coexists
• Eat adequately. Weight loss from fear of eating is a genuine problem in this condition and does no good

📋 What to expect

An ulcer with an identified and treated cause heals reliably. Symptoms usually improve within days of starting acid suppression, and healing takes four to eight weeks. Where H. pylori was the cause and eradication is confirmed, recurrence is uncommon — a complete change from the pattern of endless relapse that defined this condition before the bacterium was identified.

Ulcers that recur after apparently adequate treatment prompt a specific set of questions: was eradication actually confirmed, are NSAIDs still being taken including over the counter, is smoking continuing, and is there a rarer cause such as Zollinger-Ellison syndrome or a malignancy. Gastric ulcers in particular are re-examined endoscopically to confirm healing, because a small proportion represent cancer rather than a benign ulcer.

The treatments discussed here are stocked in the gastrointestinal category, including Prilosec (omeprazole) and the other proton pump inhibitors used both for healing and as part of eradication therapy.

When an ulcer is caused by Helicobacter pylori, antibiotics are what stop it coming back. A typical course combines an acid reducer with amoxicillin and clarithromycin, such as Biaxin XL (clarithromycin), followed by a test to confirm the bacteria are gone.

❓ Frequently asked questions

📑 Sources and editorial

• Maastricht and Houston consensus reports on the management of Helicobacter pylori infection
• American College of Gastroenterology guidelines on peptic ulcer disease and H. pylori treatment
• Marshall BJ and Warren JR — original work identifying Helicobacter pylori, Nobel Prize in Physiology or Medicine 2005
• Evidence reviews on NSAID-associated ulcer prevention with proton pump inhibitors and misoprostol
• Randomised and observational evidence on long-term proton pump inhibitor safety
• FDA prescribing information for omeprazole, esomeprazole, pantoprazole, famotidine, sucralfate and misoprostol
• Related products: gastrointestinal category
• RXshop Editorial Team — reviewed by Emily Chen, MD, MPH, Internal Medicine