H. pylori and Stomach Ulcers
A stomach bacterium that more than half the world carries. Most never notice, but it’s behind gastritis, many stomach ulcers and some stomach cancers.
Quick answer: H. pylori is a bacterium that lives in the stomach lining. Most people with it have no symptoms, but it can cause gastritis, stomach and duodenal ulcers, and raises the risk of stomach cancer. It’s found with a breath or stool test. Treatment is an acid-lowering medicine plus two antibiotics, and a later test can confirm it’s gone. Vomiting blood or black stools need emergency care.
How common. More than half the world’s population is infected. In Australia, about 3 in 10 adults are thought to carry it, with higher rates among Aboriginal and Torres Strait Islander peoples and in people from countries where it’s more common.
How you catch it. Usually in childhood, through close contact within families. Without treatment it usually stays for life.
What it can cause.
- Gastritis: inflammation of the stomach lining
- Ulcers in the stomach or duodenum (the first part of the small bowel)
- Stomach cancer and MALT lymphoma: uncommon, but the risk is higher; treatment lowers it
The other big cause of ulcers is anti-inflammatory medicines such as ibuprofen, naproxen and aspirin. Smoking adds to the risk.
Symptoms. Often none. Otherwise: burning upper tummy pain (often worse at night or when hungry), indigestion, bloating, burping, nausea or feeling full early. These overlap with reflux.
How it’s diagnosed.
- Urea breath test or stool antigen test: the usual first tests
- Stop PPIs for 2 weeks and avoid antibiotics for 4 weeks before testing, or results may be falsely negative (ask your doctor first)
- Blood antibody tests can stay positive after the bug has gone, so they aren’t used to check treatment worked
- Endoscopy (a camera into the stomach) if you’re older or have warning signs
Treatment
Experts now recommend treating everyone who tests positive. Antibiotic resistance is rising, so the exact combination depends on local guidelines and your past antibiotics.
- Step 1 · PrescriptionEradication therapyA proton pump inhibitor (such as omeprazole or esomeprazole) plus two antibiotics (often amoxicillin with clarithromycin or metronidazole), usually for 1 to 2 weeks.
- Works
- Clears the infection in most people and heals most ulcers
- Access
- GP prescription
- Watch for
- Diarrhoea, nausea and a metallic taste are common. Tell your doctor about penicillin allergy. Finish the whole course.
- Step 2 · PrescriptionAcid-lowering medicineA PPI may continue after antibiotics to let an ulcer heal. More in our PPIs guide.
- Works
- Heals ulcers and eases pain
- Access
- GP prescription
- Watch for
- Use the lowest dose for the shortest time needed.
- Step 3 · GPTest of cureA breath or stool test at least 4 weeks after finishing treatment, if your doctor advises it (always after an ulcer).
- Works
- Confirms the bacteria are gone
- Access
- GP; pathology
- Watch for
- Stop PPIs 2 weeks beforehand, as for the first test.
- Step 4 · SpecialistSecond-line treatmentA different antibiotic combination, sometimes with bismuth, if the first course fails.
- Works
- Clears most infections that survive the first course
- Access
- GP or gastroenterologist
- Watch for
- More tablets and more side effects; reinfection after successful treatment is uncommon.
Save your money
Popular, heavily marketed or often asked about, but the evidence is weak or says no.
- Home “cures” (mastic gum, garlic, probiotics alone)None reliably clear H. pylori on their own. Antibiotic treatment does.
- Blood tests to check treatment workedAntibodies linger for months after the bug is gone. Breath or stool tests are the right check.
Living with it
- Take every dose; stopping early helps resistant bacteria survive.
- Avoid anti-inflammatory painkillers if you’ve had an ulcer, unless your doctor says otherwise.
- Stopping smoking helps ulcers heal.
- Tell family members with symptoms; they may want testing too.
See your GP if
- Indigestion that keeps coming back or doesn’t settle with treatment
- Upper tummy pain, especially if it wakes you at night
- You take anti-inflammatory medicines regularly and have stomach symptoms
- You’re losing weight without trying, feel full after little food, keep vomiting, or have trouble swallowing
Get urgent help if you vomit blood or something like coffee grounds, pass black, sticky stools, have sudden severe tummy pain, or feel faint: call 000 (Australia) or your local emergency number, or go to an emergency department. Don’t drive yourself.
Outlook. Treatment clears H. pylori in most people, heals most ulcers and lowers the long-term risk of stomach cancer. Once cleared, it rarely comes back.
Common questions
What are the symptoms of H. pylori?
Most people have none. When it causes gastritis or an ulcer: burning upper tummy pain, indigestion, bloating, burping, nausea or feeling full early.
How do you get H. pylori?
Usually in childhood, through close contact within families. The exact route isn’t fully known.
Can H. pylori go away on its own?
Rarely. Without treatment it usually stays in the stomach for life.
Is H. pylori contagious?
It can spread between people in close contact, mostly in childhood. Reinfection in adults after treatment is uncommon.
Why do I have to stop my PPI before the test?
PPIs suppress the bacteria and can make breath and stool tests falsely negative. Most guidelines advise 2 weeks off first.
Can H. pylori cause cancer?
It raises the risk of some stomach cancers. Treating it lowers that risk.
Evidence and more information
- Healthdirect: Helicobacter pylori
- NHS: Stomach ulcer
- NICE QS96: Testing conditions for Helicobacter pylori
- Malfertheiner et al, Gut 2022: Maastricht VI/Florence consensus report on H. pylori
- NHS Tayside: H. pylori treatment guidance
maladywise.com/h-pylori/