The commonest cause of diarrhoea in children is acute infective gastroenteritis, but there are certain conditions that develop in childhood and infancy and require special attention. The presentation of small amounts of redcurrant jelly-like stool with intussusception should also be kept in mind. Of the many causes only a few are commonly seen. The two commonest causes are infective gastroenteritis and antibiotic-induced diarrhoea.
Important causes of diarrhoea in children are:
overfeeding (loose stools in newborn)
sugar (carbohydrate) intolerance
food allergies (e.g. milk, soy bean, wheat, eggs)
malabsorption states: cystic fibrosis, coeliac disease
Note: Exclude surgical emergencies (e.g. acute appendicitis), infections (e.g. pneumonia), septicaemia, otitis media <5 years.
Note: Dehydration from gastroenteritis is an important cause of death, particularly in obese infants (especially if vomiting accompanies the diarrhoea).
It is an illness of acute onset, of less than 10 days’ duration associated with fever, diarrhoea and/or vomiting, where there is no other evident cause for the symptoms.5
Mainly rotavirus (developed countries) and adenovirus: viruses account for about 80%
Bacterial: C. jejuni and Salmonella sp. (two commonest), E. coli and Shigella sp.
Protozoal: G. lamblia, E. histolytica, Cryptosporidium
Food poisoning—staphylococcal toxin
Differential diagnoses. These include septicaemia, urinary tract infection, intussusception, appendicitis, pelvic abscess, partial bowel obstruction, diabetes mellitus and antibiotic reaction4 (see TABLE 44.9).
Table 44.9Differential diagnosis of acute diarrhoea and vomiting in children ||Download (.pdf) Table 44.9 Differential diagnosis of acute diarrhoea and vomiting in children
|Bowel infection: |
|Systemic infection |
|Abdominal disorders: |
|Urinary tract infection |
|Antibiotic reaction |
|Diabetes mellitus |
Anorexia, nausea, poor feeding, vomiting, fever, diarrhoea (fever and vomiting may be absent)
Fluid stools (often watery) 10–20 per day
Crying—due to pain, hunger, thirst or nausea
Bleeding—uncommon (usually bacterial)
Viral indication: large volume, watery, typically lasts 2–3 days, systemic symptoms uncommon.
Bacterial indication: small motions, blood, mucus, abdominal pain and tenesmus.
Dehydration: must be assessed (see TABLE 44.10).
Table 44.10Assessment of hydration2 ||Download (.pdf) Table 44.10 Assessment of hydration2
| ||Mild ||Moderate ||Severe |
|Body weight loss ||4–5% ||6–9% ||≥9% |
|Symptoms/general observations || |
Infants: drowsy, limp, cold, sweaty, cyanotic limbs, comatose
Older: apprehensive, cold and sweaty, cyanotic limbs
|Signs ||Normal || |
Dry mucous membranes, absent tears
Mildly sunken eyes
Rapid feeble pulse
Sunken eyes and fontanelles
Very dry mucous membranes
|Pinched skin test ||Normal (<2 seconds) ||Retracts slowly (1–2 seconds) ||Retracts very slowly (>2 seconds) |
|Urine output ||Normal ||Decreased ||Nil |
|Treatment ||Oral rehydration: ||Oral rehydration: || |
Admit to hospital
Urgent IV infusion: isotonic fluid (0.9% saline)
Start with bolus 20 mL/kg
Management is based on the assessment and correction of fluid and electrolyte loss.5,6 Since dehydration is usually isotonic with equivalent loss of fluid and electrolytes, serum electrolytes will be normal.
Note: The most accurate way to monitor dehydration is to weigh the child, preferably without clothes, on the same scale each time. However, the easiest is clinical assessment (e.g. vomiting, no urine, lethargy and thirst).
Drugs: antidiarrhoeals, anti-emetics and antibiotics
Lemonade or similar sugary soft drink: osmotic load too high, can use if diluted 1 part to 4 parts water but sugar may be poorly tolerated
To treat or not to treat at home
Treat at home—if family can cope, vomiting is not a problem and no dehydration.
Admit to hospital—if dehydration or persisting vomiting or family cannot cope; also infants <6 months and high-risk patients.
Advice to parents (for mild-to-moderate diarrhoea)
If applicable, remove child from day care or school and keep away from food preparation areas. Advise about hygiene, including handwashing and napkin disposal. If children are not dehydrated, encourage eating and drinking as tolerated.
Give small amounts of fluids often
Start solids after 24 hours
Continue breastfeeding (should be increased in frequency, e.g. hourly)
Continue formula feeding if tolerated or resume it after 24 hours.
Consider stool culture and test for rotavirus for symptoms that persist and worsen
Give fluids, a little at a time and often (e.g. 5 mL every 1–2 minutes by spoon or syringe or 50 mL every 15 minutes if vomiting a lot). A good method is to give 200 mL (about 1 cup) of fluid every time a watery stool is passed or a big vomit occurs.
The ideal fluid is Gastrolyte or Repalyte (new formulation). Other suitable oral rehydration preparations are WHO-recommended solutions Electrolade and Glucolyte.
A new product is Hydralyte paediatric rehydration, which is a solution as an ‘ice-block’ formulation:
Warning: Do not use straight lemonade or mix up Gastrolyte with lemonade or fluids other than water.
|Alternatives are: |
| ||1 part to 6 parts water |
| ||1 teaspoon to 120 mL water |
| ||1 teaspoon to 120 mL water |
| ||1 part to 16 parts water |
| ||1 part to 4 parts water |
Method of assessing fluid requirements3
Fluid loss (mL) = % dehydration × body weight (kg) × 10
Maintenance (mL/kg/24 h): 1–3 mo: 120 mL; 4–12 mo: 100 mL; >12 mo: 80 mL
Allow for continuing loss.
Example: 8 month 10 kg child with 5% dehydration:
Fluid loss = 5 × 10 × 10 = 500 mL
Maintenance = 100 × 10 = 1000 mL
Total 24-hour requirement (min.) = 1500 mL
Approximate average hourly requirement = 60 mL
Aim to give more (replace fluid loss) in the first 6 hours.
Rule of thumb: give 100 mL/kg (infants) and 50 mL/kg (older children) in first 6 hours.
Reintroduce your baby’s milk or formula diluted to half strength (i.e. mix equal quantities of milk or formula and water). Their normal food can be continued but do not worry that your child is not eating food. Solids can be commenced after 24 hours. Best to start with bread, plain biscuits, jelly, stewed apple, rice, porridge or non-fat potato chips. Avoid fatty foods, fried foods, raw vegetables and fruit, and wholegrain bread.
Increase milk to normal strength and gradually continue reintroduction to usual diet.
Breastfeeding. If your baby is not vomiting, continue breastfeeding but offer extra fluids (preferably Gastrolyte) between feeds. If vomiting is a problem, express breast milk for the time being while you follow the oral fluid program.
Note: Watch for lactose intolerance as a sequela—explosive diarrhoea after introducing formula. Replace with a lactose-free formula.
If acute invasive or persistent Salmonella are present, give antibiotics (ciprofloxacin or azithromycin).
CHRONIC DIARRHOEA IN CHILDREN6
Synonyms: carbohydrate intolerance, lactose intolerance.
The commonest offending sugar is lactose.
Diarrhoea often follows acute gastroenteritis when milk is reintroduced into the diet (some recommend waiting for 2 weeks). Stools may be watery, frothy, smell like vinegar and tend to excoriate the buttocks. They contain sugar. Exclude giardiasis.
Line the napkin with thin plastic and collect fluid stool.
Mix 5 drops of liquid stool with 10 drops of water and add a Clinitest tablet (detects lactose and glucose but not sucrose).
A positive result indicates sugar intolerance.
Diagnosis: lactose breath hydrogen test.
Remove the offending sugar from the diet.
Use milk preparations in which the lactose has been split to glucose and galactose by enzymes, or use soy protein.
Note: Most milk allergies improve with age.
Toddler’s diarrhoea (‘cradle crap’)
A clinical syndrome of loose, bulky, non-offensive stools with fragments of undigested food in a well, thriving child. The onset is usually between 8 and 20 months. Associated with high fructose intake (fruit juice diarrhoea).
Diagnosis by exclusion; treatment by dietary adjustment.
Cow’s milk protein intolerance7
This is not as common as lactose intolerance. Diarrhoea is related to taking a cow’s milk formula and relieved when it is withdrawn.
Allergic responses to cow’s milk protein may result in a rapid or delayed onset of symptoms. Delayed onset may be more difficult to diagnose, presenting with diarrhoea, malabsorption or failure to thrive.
It is diagnosed by unequivocal reproducible reactions to elimination and challenge. If diagnosed, remove cow’s milk from the diet and replace with either soy milk, a hydrolysed or an elemental formula (see CHAPTER 80).
Inflammatory bowel disorders
These disorders, which include Crohn disease and ulcerative colitis, can occur in childhood. A high index of suspicion is necessary to make an early diagnosis. Approximately 5% of cases of chronic ulcerative colitis have their onset in childhood.5
Chronic enteric infection
Responsible organisms include Salmonella sp., Campylobacter, Yersinia, G. lamblia and E. histolytica. With persistent diarrhoea, it is important to obtain microscopy of faeces and aerobic and anaerobic stool cultures. G. lamblia infestation is not an uncommon finding and may be associated with malabsorption, especially of carbohydrate and fat. Giardiasis can mimic coeliac disease.
(See earlier in chapter.)
Clinical features in childhood:
usually presents at 9–18 months, but any age
previously thriving infant
anorexia, lethargy, irritability
failure to thrive
offensive frequent stools
Diagnosis: duodenal biopsy (definitive).
Treatment: remove gluten from diet.
Cystic fibrosis, which presents in infancy, is the commonest of all inherited disorders (1 per 2500 live births). Refer to CHAPTER 18.
ACUTE GASTROENTERITIS IN ADULTS
Invariably a self-limiting problem (1–3 days)
Possible constitutional symptoms (e.g. fever, malaise, nausea, vomiting)
Other meal-sharers affected → food poisoning
Consider dehydration, especially in the elderly
Consider possibility of enteric fever
The symptoms are usually as above, but very severe diarrhoea, especially if associated with blood or mucus, may be a feature of a more serious bowel infection such as amoebiasis. Possible causes of diarrhoeal illness are presented in TABLE 14.1, in CHAPTER 14. Most traveller’s diarrhoea is caused by E. coli, which produces a watery diarrhoea within 14 days of arrival in a foreign country. (For specific treatment refer to the section on Traveller’s diarrhoea in CHAPTER 14.)
Persistent traveller’s diarrhoea
Any traveller with persistent diarrhoea after visiting less developed countries, especially India and China, may have a protozoal infection such as amoebiasis or giardiasis.
If there is a fever and blood or mucus in the stools, suspect amoebiasis. Giardiasis is characterised by abdominal cramps, flatulence and bubbly, foul-smelling diarrhoea.