Dyspepsia, GORD and peptic ulceration have a number of causes. Hypersensitive tissues may respond to the increased acid produce in digestion, or the volume of food may stretch the stomach and weaken the oesophageal sphincter, resulting in reflux. In obesity and pregnancy, pressure on the stomach after a meal causes reflux. Hormonal changes in pregnancy may also trigger indigestion.3

Some foods such as coffee and chocolate, as well as smoking and alcohol, and drugs such as nitrates, calcium-channel blockers, beta-agonists, anti-cholinergics and xanthines can relax the lower oesophageal sphincter. Alcohol can also stimulate more acid production.1,7

Non-steroidal anti-inflammatory drugs can affect the stomach lining in a number of ways. Mechanisms include irritating the epithelium, impairing mucosal barrier properties, suppressing gastric prostaglandin synthesis, and reducing gastric mucosal blood flow to delay the repair process.9

Gastroparesis is the stomach taking longer to eliminate acid, prolonging the time that sensitive tissue may be exposed to it. Fatty foods and drugs such as opiates and antidepressants can delay the emptying of stomach contents. Gastroparesis is also a symptom of poorly controlled diabetes, and a complication of some gastric surgery. It can also occur with diseases such as Parkinson's, scleroderma and amyloidosis.10

Stress, anxiety and depression are associated with functional dyspepsia.11 Hiatus hernia, GORD, peptic ulcers (stomach and duodenal), Helicobacter pylori infection, and stomach cancer can all have indigestion symptoms.3

Acid reflux and heartburn are sometimes a feature of gluten enteropathy or coeliac disease. It may also be an issue in ulcerative colitis when steroid therapy is being tapered down.12,13

Barrett's oesophagus, an abnormality of the cells lining the oesophagus, is associated with GORD.1 After prolonged exposure to acid reflux, possibly years, cells lining the oesophagus start to change into a form more predisposed to cancer. Prevalence is uncertain, but European studies have indicated 1%-2% of the general population may have Barrett's oesophagus, and around 10% of people with chronic GORD may have it.14,15 

Many people with Barrett's oesophagus are unaware they have the condition, while others will have GORD-like symptoms. Of concern is that 1%-5% of people with Barrett's oesophagus can eventually develop oesophageal cancer, although the pre-cancerous stage may take a decade to progress.15,16