Dysphagia is difficulty in swallowing
Heartburn is a retrosternal or epigastric burning sensation that spreads upwards to the throat.
Dyspepsia and indigestion
These are terms often used by lay people to describe any symptom, e.g. nausea, heartburn, acidity, pain or distension, that occurs as a result of eating or drinking. They may also be used to describe an inability to digest food. Careful questioning is required to elicit the exact nature of the patient’s complaint. ‘Indigestion’ is common; 80% of the general population will have had indigestion at some time.
Flatulence is the term used to describe excessive wind. It indicates belching, abdominal distension (see below) or the passage of flatus per rectum. Excessive belching is not usually associated with organic disease and is a common functional disorder. It is due to air swallowing (aerophagy), which many people do subconsciously. Some of the swallowed air is passed into the intestines, where most is absorbed. Intestinal bacterial breakdown of food, particularly high-fibre legumes, also produces a small amount of gas. Flatus consists of nitrogen, carbon dioxide, hydrogen and methane. On average, flatus is passed 10-20 times per day.
Hiccups are due to involuntary diaphragmatic contractions with closure of the glottis and are extremely common. Rarely they become continuous, when treatment with chlorpromazine 50 mg three times a day or diazepam 5 mg three times daily may be effective.
The vomiting centres are located in the lateral reticular formation of the medulla and are stimulated by the chemoreceptor trigger zones (CTZ) in the floor of the fourth ventricle, and also by vagal afferents from the gut. The CTZ are directly stimulated by drugs, motion sickness and metabolic causes. There are three stages:
• Nausea-a feeling of wanting to vomit often associated with autonomic effects including hypersalivation, pallor and sweating
• Retching-a strong involuntary effort to vomit
• Vomiting-the expulsion of gastric contents through the mouth Many gastrointestinal conditions are associated with vomiting, but nausea and vomiting without pain is frequently non-gastrointestinal in origin.
CHRONIC NAUSEA AND VOMITING with no other abdominal symptoms are usually due to psychological causes. Early morning vomiting is seen in pregnancy, alcohol dependence and some metabolic disorders, e.g. uraemia.
Constipation is difficult to define in terms of frequency of bowel action because there is considerable individual and geographical variation. Patients usually consider themselves constipated if their bowels are not opened on most days. The difficult passage of hard stools is also regarded as constipation, irrespective of stool frequency. Normal daily stool weight in the UK is only 50-300 g, whereas in developing countries with a high fibre intake stool weight is 500 g or more with bowel actions two to three times per day.
Diarrhoea is extremely common; a single episode is usually due to dietary indiscretion. True diarrhoea implies the passing of increased amounts (>300 g per 24 hours) of loose stool and is different from the frequent passage of small amounts of stool, which is commonly seen in functional bowel disease. The consistency of the stools is important; watery stools of large volume are always due to an organic cause. Bloody diarrhoea usually implies colonic disease. Diarrhoea can be either acute or chronic. If it is acute, infective causes must be looked for.