Most people experience indigestion from time to time. It usually happens after a big or fatty meal, or after you've eaten something that usually gives you a bloated, uncomfortable feeling in the upper stomach.
Occasional indigestion affects most people, and can usually be prevented by not eating huge meals, or by avoiding foods that make you feel uncomfortable.
But there are more serious complications than the occasional feeling of bloatedness or heartburn.
Heartburn is the symptom for a spectrum of clinical conditions called gastro-oesophageal reflux disease (GORD), and it's believed that the incidence of GORD is on the rise in many countries.
Heartburn in the presence of a normal oesophagus and lower oesophageal sphincter is called "functional heartburn". In the presence of inflammation and ulceration of certain parts of the oesophagus (gullet), it's called "erosive GORD".
• Oesophageal stricture: Scar tissue forms in the gullet, narrowing the passage for food and impeding swallowing.
• Oesophageal ulcer: The stomach acid can erode the lining of the oesophagus, producing a painful, bleeding sore.
• Barrett's oesophagus: In this condition, the oesophageal lining changes in a way that is linked to an increased risk of oesophageal cancer.
The usual heartburn remedies aren't enough to combat GORD, or may ease symptoms only temporarily. Treating GORD may involve stronger medications and sometimes even surgery.
Another of the stomach disorders are peptic ulcers. In order to digest food, the stomach glands produce a mixture of acid and pepsin. Usually a layer of protective mucus prevents damage to the stomach lining. When the balance between the acids and the protective mucus is disturbed, the stomach is vulnerable to direct attack.
A third of the stomach disorders is called non-ulcer dyspepsia. The main symptoms of this condition are a burning, aching feeling in the upper part of the abdomen and nausea. At times of stress, the feeling of discomfort can become severe.
Doctors usually first rule out GORD, peptic ulcers and gallstones before making this diagnosis. The causes of non-ulcer dyspepsia aren't clear and possibilities are many – from other intestinal tract disorders, a particular sensitivity to certain foods or to stomach acid, through to lifestyle choices.