Abdominal pain after eating: common causes and when to see a doctor

Abdominal pain after eating is not a diagnosis in itself. It is a symptom that can come from several parts of the digestive system, and the useful question is usually what kind of pain it is, where it sits and how it behaves over time. A single episode after an unusually rich meal is very different from pain that appears after most meals for weeks.

The NHS notes that most stomach aches are not serious and settle within a few days. It also lists the common explanations in a simple way: feeling full and bloated after eating with heartburn and nausea suggests indigestion; feeling bloated and passing a lot of wind suggests trapped wind; being unable to poo suggests constipation; and watery poo with sickness points to a stomach bug or food poisoning.

Less common causes listed by the NHS include period pain, appendicitis, irritable bowel syndrome, kidney stones and gallstones. The NHS is clear that people should not self-diagnose and should see a GP if they are worried.

Several conditions are linked to pain around meals. They overlap, which is why a GP will ask detailed questions before deciding what to test.

• Indigestion is often caused by stomach acid irritating the lining of the stomach or throat. The NHS lists certain foods and drinks, being overweight, smoking, pregnancy, stress and some medicines such as anti-inflammatory painkillers as things that can cause or worsen it.

• Stomach ulcers are mainly caused by infection with Helicobacter pylori bacteria or by regular use of anti-inflammatory painkillers such as ibuprofen, and are more common in smokers and with increasing age.

• IBS has no single test. The NHS says flare-ups can be triggered by alcohol, caffeine, spicy or fatty food, stress and anxiety, or regular antibiotic use.

• Gallstones are common and often cause no symptoms at all. The NHS says they are more likely if you are over 40, female, living with obesity, eat a diet high in fat and low in fibre, have lost weight quickly, or have a condition such as diabetes or Crohn's disease.

The NHS separates tummy pain into three levels of urgency. For indigestion or mild pain it often says a pharmacist can help. For stomach ache it advises an urgent GP appointment or NHS 111 if the pain gets much worse, does not go away or keeps coming back, if bloating does not settle, if you have problems swallowing, are pregnant, are losing weight without trying, notice blood from your bottom, or have diarrhoea that lasts more than a few days.

For indigestion specifically, the NHS says to see a GP if you keep getting it, are in severe pain, have lost a lot of weight without meaning to, have difficulty swallowing, keep being sick, have iron deficiency anaemia, feel a lump in your stomach, or have bloody vomit or poo.

• Call 999 or go to A&E if a stomach ache came on very suddenly or is severe, it hurts when you touch your tummy, you are vomiting blood or vomit that looks like ground coffee, your poo is bloody or black, sticky and extremely smelly, you cannot pee, you cannot poo or fart, you have chest pain, or you have diabetes and are vomiting.

• For gallstone-type pain, the NHS says to call 999 or go to A&E for sudden severe tummy pain, pain spreading to the back with being sick, a very high temperature or feeling hot, cold or shivery, or yellow skin or eyes. Pain lasting longer than 30 minutes should prompt an urgent GP appointment or NHS 111.

• The NHS asks people not to drive themselves to A&E: ask someone else to drive or call 999.

Most people start with a GP appointment. The GP will ask when the pain happens in relation to meals, where it is, what makes it better or worse, whether you have noticed weight loss, sickness or changes in your poo, and which medicines you take, including over-the-counter painkillers. They may feel your tummy and weigh you.

Tests depend on the suspected cause. For a possible stomach ulcer the NHS says a GP may arrange a breath test for H. pylori, a poo sample test or a blood test, and may refer you for a gastroscopy, where a thin flexible tube with a camera is passed through the mouth into the stomach. For possible gallstones, the NHS says an ultrasound scan and a blood test are used. For suspected IBS there is no specific test, but a GP may arrange a blood test to look for problems such as coeliac disease and poo tests to check for infection and inflammatory bowel disease.

Keeping a simple diary of what you ate, when pain began and how long it lasted can make the appointment more useful. The NHS suggests writing down symptom details beforehand so you remember them.

Treatment follows the cause. For indigestion, the NHS suggests cutting down on tea, coffee, cola and alcohol, raising your head and shoulders in bed, losing weight if you are overweight, not eating 3 to 4 hours before bed, avoiding rich, spicy or fatty foods, not smoking, and not taking ibuprofen or aspirin unless prescribed. A pharmacist can recommend antacids, alginates or proton pump inhibitors.

For a stomach ulcer, the NHS says treatment depends on the cause and may include antibiotics for H. pylori and medicines such as proton pump inhibitors to reduce stomach acid, usually for 1 week to 2 months. Gallstones that cause symptoms are usually treated by surgery to remove the gallbladder, and stones in the bile duct may be cleared with a procedure called ERCP. While waiting for surgery the NHS says people may take paracetamol and ibuprofen, be offered stronger painkillers for severe pain, and be advised to avoid trigger foods or follow a low-fat diet.

For IBS, the NHS describes lifestyle, diet and medicine options that a GP can discuss with you.

The outlook is usually good once the cause is found. Indigestion and IBS are often managed long term with lifestyle changes and medicines. Ulcers generally heal with treatment, although the NHS stresses that untreated ulcers can bleed, cause iron deficiency anaemia or perforate. Gallstone complications are described as rare, but they include inflammation of the gallbladder or pancreas and jaundice.

In the UK, the usual route is through a GP, with blood tests, breath or stool tests, ultrasound and referral for endoscopy arranged through the NHS. Some people choose to see a private gastroenterologist for quicker access to endoscopy or imaging. The same underlying tests are used either way, and a GP can explain which are likely to be useful in your situation.