K52.9
DESCRIPTION
Chronic diarrhoea: diarrhoea for longer than two weeks.
Chronic diarrhoea results in significant morbidity and mortality associated with poor nutrition. Chronic diarrhoea is most frequently due to:
- Temporary loss of disaccharidase activity in the intestinal microvillous brush border, e.g. lactase loss; or luminal infection/infestation, which may be non-specific bacterial overgrowth.
- Rare causes include food allergies, cystic fibrosis and coeliac disease.
DIAGNOSTIC CRITERIA
Clinical
- Chronic diarrhoea without weight loss or dehydration – consider Toddler’s diarrhoea.
- Chronic diarrhoea with weight loss and dehydration – consider small bowel mucosal injury with multiple pathophysiological mechanisms, e.g. lactose intolerance, small bowel bacterial overgrowth and immunosuppression.
- Chronic diarrhoea with weight loss but no dehydration – consider a malabsorption syndrome, e.g. coeliac disease, allergic enteropathy, cystic fibrosis, etc.
- Consider the possibility of HIV infection.
- In the presence of abdominal pain, bloody stools, weight loss, perianal disease or extraintestinal features such as arthritis or uveitis, consider inflammatory bowel disease and refer to an appropriate specialist.
Investigations
Where weight gain falters, dehydration recurs, the child is ill or the diarrhoea continues:
- full blood count,
- serum proteins
- urine and stool microscopy, culture and sensitivity tests (MCS),
- positive stool-reducing substances if on a lactose-containing diet. Stool pH < 5.5 also suggests carbohydrate malabsorption,
- faecal elastase.
REFERRAL
- Inability to maintain hydration (persisting watery diarrhoea even when fasting).
- Lack of local resources to support the stepwise protocol at any step.
- All cases not responding by day 12–13 of the stepwise protocol.
- If cystic fibrosis, allergic enteropathy or coeliac disease is suspected, but difficult to diagnose due to lack of local resources.