I feel it most acutely on Christmas Day, after an enormous lunch, I achieve the impossible and eat three slices of pavlova, despite insisting I will stop at two.
Indigestion usually happens because we've eaten too much, or too quickly. Sometimes it can be triggered by spicy food, excessive coffee or alcohol, or doing physical activity too soon after eating.
Australians experience reflux and heartburn regularly, while occasional indigestion can be relieved with over-the-counter medicines.
In many cases, acid-lowering medications called proton pump inhibitors – or PPIs – are prescribed by doctors who believe the symptoms are caused by a condition called gastro-oesophageal reflux disease (GORD).
But new research published in the New England Journal of Medicine.
"Physicians and patients should not assume that only because they have heartburn especially especially when the heartburn does not go away with the proton pump inhibitors," Dr. Spechler, from Baylor University Medical Center, told the Health Report.
PPIs are highly effective, and among the most widely sold medications in the world. But they're often used longer than necessary, and these latest findings suggest many people are taking them incorrectly – or unnecessarily.
First things first: what causes heart burn?
Every time we eat, our food is chewed, swallowed and pushed down our oesophagus – the tube that connects our mouth to our stomach.
At the base of the oesophagus, a ring of muscles relaxes from food, and tightens to prevent stomach acid from escaping.
Occasionally, even in healthy individuals, stomach acid is inadvertently pushed back into the oesophagus, where it can cause a burning sensation in the chest or throat.
This is known as heartburn, and in most people, it can be relieved by taking over-the-counter antacid medicines (which neutralize stomach acid) or simply waiting.
For some people, however, heartburn can be persistent.
When it occurs more than twice a week, it is usually thought to be GORD – and the result of a "leaky valve mechanism at the end of the oesophagus".
"In many ways it's a plumbing issue," said Dr. Spechler.
"[The valve] malfunctions in reflux disease so that material from the stomach can reflux back into the oesophagus.
"The acid in there can give you a burning sensation… and if the material comes all the way back to your mouth, that's regurgitation."
How to treat heartburn
For people with persistent heartburn, avoiding certain foods and drinks.
Health professionals recommend lifestyle changes, including losing weight, quitting smoking, eating less meals, and avoiding food before vigorous exercise, and two or three hours before sleeping.
But to create a long-lasting reduction of stomach acid, people are also usually prescribed a course of PPIs.
"Though reflux continues, without the acid, generally the burning sensation goes away," said Dr Spechler.
However, PPIs don't always work.
"In up to 30 to 40 per cent of people who take these drugs, they will say, 'My symptoms have not gone away, and I'm not satisfied with the relief I'm getting'," said Dr Spechler.
One alternative to PPIs is surgery (to fix the leaky valve mechanism in the oesophagus) – but the evidence has not been clear as to whether surgical intervention is better than medication.
To find out, Dr Spechler and his colleagues put it to the test, comparing medicines that reduce stomach acid, drugs that relax the muscles in the throat, and throat surgery.
Reflux disease isn't always the cause
"PPI-refractory heartburn" (heartburn that doesn't respond to PPIs) actually had GORD.
We We started with 366 patients and ended up with 78 were and we think that's a very important part of the study, Dr said Dr Spechler.
"Many of the patients who were qualified for the study did not have acid reflux, but they had reflux that was causing symptoms.
"[The stomach] "If you have a plumbing problem there."
The causes of heartburn are many and varied, Dr. Spechler said, and not specific to reflux disease either.
You You can have other diseases, that he said.
"Problems with the muscles in the oesophagus, for example. There is a food allergy problem that involves the oesophagus that can also give you heartburn.
"Many patients who have PPI-resistant heartburn have what we call 'functional heartburn'" meaning something that isn't necessarily an organic problem with the stomach or oesophagus. "
PPIs were simply not taking their medicines correctly.
"The proton pump inhibitors, because of the way they work, it's very important that they are dosed around mealtimes," said Dr Spechler.
"The reason is that the PPIs inhibit the actual acid-making cells in the stomach. In order to inhibit them, the cells are active.
Dr. Spechler said that as soon as the researchers explained how to take the medication correctly – 30 to 60 minutes before meals – many patients with GORD did in fact get relief.
"I think that's just a very simple thing that doctors and patients can do… make sure that they are taking the drugs correctly."
Finding the right treatment
Whatever the cause of heartburn, Dr Spechler said, it was important to identify and avoid unnecessary or ineffective treatment.
"The reason that it is very important to identify… is because you don't want to have a reflux in someone who doesn't have reflux," he said.
Among the 78 patients found to have GORD that was truly unresponsive for PPIs, the researchers found that surgery was the most effective solution, both for acid and non-acid reflux.
"In some people we found that reflux of non-acid material was giving them the sensation of heartburn. And those patients did very well, with the operation," he said.
"The fact that they responded well to surgery means that, yes, they did in fact have a plumbing problem that could be corrected with an operation."