Diarrhoea: causes and symptoms
Diarrhoea may have many different causes including a change in diet, food intolerance (e.g. lactose), inflammatory bowel disorder, medications (e.g. antibiotics, magnesium-containing antacids), a bacterial infection (food poisoning) or a viral infection (e.g. rotavirus in children).
Diarrhoea in very young children is often caused by rotavirus. There is now a vaccine available that can prevent gastroenteritis (or reduce the risk of severe gastroenteritis) caused by rotavirus infection. The vaccine is given as part of the routine childhood immunisation schedule.
Diarrhoea may also be caused by diet, for example, too much fruit or fruit juice. People with diarrhoea, especially the very young and the very elderly, are at risk of becoming rapidly dehydrated. This requires immediate medical attention.
What can you do to help?
If you have diarrhoea you should:
- not drink flat lemonade or other soft drinks, as the high glucose content may draw fluid into the gut, causing more diarrhoea;
- restrict food intake for 24 hours (for children, give only clear fluids such as electrolyte replacement fluid or water);
- eat only bland, dry foods after 24 hours, avoiding grains and uncooked fruit and vegetables;
- restrict fats and dairy food for 48 hours; and
- watch for signs of dehydration, especially in children and the elderly.
Some children may experience lactose intolerance (inability to digest milk sugars) for some time after the diarrhoea has settled. If this is the case, you should re-introduce milk products gradually.
When should you seek medical advice?
You should seek medical advice if:
- a child or elderly person has severe diarrhoea, as they may become rapidly dehydrated;
- diarrhoea lasts more than 48 hours in a normal adult;
- there is bright red blood in the faeces, or stools are dark and tarry;
- the faeces have high fat content, which may be seen as pale, greasy, foul smelling stools that are difficult to flush;
- symptoms include fever or stomach cramps, or a general feeling of being unwell;
- you have vomiting, weakness and dizziness;
- there are signs of dehydration such as lethargy, loss of skin elasticity, dry mucous membranes, sunken eyes, decreased urine output, rapid heart rate or confusion;
- constipation alternates with the diarrhoea;
- the diarrhoea was acquired while travelling; or
- the diarrhoea occurred after recent treatment with an antibiotic.
Last Reviewed: 02 October 2007
