Painkillers (NSAIDs) and Your Gut

Non-steroidal anti-inflammatory drugs (NSAIDs)

Ibuprofen, diclofenac, naproxen, ketorolac, aspirin, mefenamic acid, celecoxib (a type that is gentler on the stomach but not risk-free)

NSAIDs reduce pain, fever and inflammation by blocking enzymes called COX. The same enzymes also help protect the lining of the stomach and bowel and keep blood flowing to the kidneys. When they are blocked, the stomach lining is more easily damaged by acid, ulcers can form, and bleeding can occur. They can also irritate the small bowel and colon, and may trigger a flare in people with inflammatory bowel disease (IBD).

Use the lowest effective dose for the shortest time, with food, and follow the label or your doctor’s advice. Avoid taking more than one NSAID at once (including creams and tablets from different brands containing the same ingredient). Ask whether paracetamol (acetaminophen) at the recommended dose is enough for you, since it does not usually irritate the stomach, though it must not be overused because it can harm the liver. If you must use an NSAID long term, ask your doctor about a stomach-protecting medicine and a check for Helicobacter pylori. Do not take NSAIDs if you have had a stomach ulcer or bleeding, kidney or liver disease, heart failure, or take blood thinners unless a doctor says it is safe. Do not give aspirin to children or teenagers unless a doctor prescribes it.

• Vomiting blood or “coffee-ground” material, or black, tarry stools — Signs of bleeding from an ulcer. This is an emergency: go to the emergency department or call emergency services now.

• Sudden severe belly pain that spreads and makes the abdomen hard and painful to touch — Could be a perforated ulcer (a hole in the stomach wall). Go to the emergency department now.

• Dizziness, fainting, pale skin, breathlessness or unusual tiredness — May mean slow blood loss and anaemia. See a doctor promptly; urgent care if severe.

• Swollen legs or face, much less urine, or sudden weight gain — NSAIDs can harm the kidneys and cause fluid retention, particularly in older people, those with liver or kidney disease or on water pills. Contact your doctor promptly.

• Rash, wheeze, or swelling of the lips, face or throat — Could be a serious allergic reaction. Call emergency services now.

• New or worse diarrhoea with blood or belly cramps in someone with IBD — NSAIDs may trigger a flare. Contact your IBD team promptly; urgent care if severe.

The risk of bleeding rises sharply if you combine NSAIDs with aspirin, blood thinners, steroids, or SSRI antidepressants. They can reduce the effect of some blood-pressure medicines and water pills and raise kidney risk when taken with them. They can raise levels of methotrexate and lithium. Alcohol increases stomach risks. Always tell your doctor and pharmacist about all painkillers, including ones bought without a prescription and herbal products.

If you must take an NSAID for a long time, your doctor may check your blood count, kidney function and blood pressure, and may test for Helicobacter pylori and prescribe a stomach-protecting medicine. Report any new indigestion promptly instead of treating it yourself for weeks.

Stop the NSAID and seek advice if you get stomach pain, black stools, vomiting blood, or reduced urine. Do not stop prescribed low-dose aspirin or another heart/stroke protective medicine on your own; talk to your doctor first.

NSAIDs are generally avoided in pregnancy, especially from about 20 weeks, and need caution in breastfeeding. Paracetamol at the usual dose is often the first choice, but check with your doctor or pharmacist first.

Many NSAIDs are available over the counter, and people often combine them for headache or joint pain. Fasting during Ramadan with an empty stomach can increase stomach irritation; talk to your doctor about safer pain options and timing.

• Is it safe for me to take an NSAID, given my stomach, kidneys, heart and other medicines?

• What can I use instead for pain?

• Should I take a stomach-protecting medicine or be tested for H. pylori?

• Does my IBD, ulcer history or liver disease mean I should avoid them completely?

• How long can I safely use them?

This guide comes from the Saudi Gastroenterology Association (SGA) patient library, prepared by the Approved for publication by SGA; individual clinician review is ongoing. Last reviewed: 2026-04-24. It is for education and does not replace your doctor's advice.