Gastroenteritis in Children

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management | References

Definition

Gastroenteritis is an inflammation of the gastrointestinal tract, involving both the stomach and intestines, and is typically caused by infection with viruses, bacteria, or parasites. In children, it is most commonly caused by viral infections and leads to symptoms such as diarrhoea, vomiting, and abdominal pain. The condition can result in dehydration, which is the primary concern in managing gastroenteritis.

Aetiology

The most common causes of gastroenteritis in children include:

• Viral infections: Rotavirus (common in children under 5), norovirus, and adenovirus.
• Bacterial infections: Salmonella, Escherichia coli (E. coli), Shigella, and Campylobacter.
• Parasitic infections: Giardia lamblia, Cryptosporidium.
• Non-infectious causes: Food intolerances or allergies (less common).

Pathophysiology

Gastroenteritis is caused by an infectious agent that invades the mucosal lining of the gastrointestinal tract, leading to inflammation. This inflammation impairs the absorption of water and electrolytes, resulting in diarrhoea and dehydration. Vomiting is often caused by irritation of the stomach lining or the body's response to toxins produced by certain bacteria or viruses. In bacterial gastroenteritis, toxins can also directly damage the intestinal lining, leading to more severe symptoms.

Risk Factors

• Young age (children under 5 years are more vulnerable).
• Attending daycare or school, increasing exposure to infections.
• Consumption of contaminated food or water.
• Immunocompromised children, including those with chronic illnesses.
• Poor hand hygiene or living in areas with poor sanitation.
• Recent travel to areas with a higher risk of gastrointestinal infections.

Signs and Symptoms

• Diarrhoea (watery or bloody).
• Vomiting.
• Abdominal pain or cramping.
• Fever (especially with bacterial infections).
• Dehydration (dry mouth, sunken eyes, decreased urine output, lethargy).

Investigations

Most cases of viral gastroenteritis are self-limiting and do not require investigations. However, in severe or prolonged cases, investigations may be warranted:

• Stool sample: To test for bacteria, parasites, or viruses if bloody diarrhoea, prolonged illness, or recent travel.
• Blood tests: FBC and electrolytes may be indicated in severely ill or dehydrated children.
• Urinalysis: To assess dehydration status.

Management

Management focuses on rehydration and symptomatic relief. Most cases of gastroenteritis in children are mild and can be treated at home with supportive care.

First-line Treatment:

• Oral rehydration therapy (ORT): The primary treatment for mild to moderate dehydration. ORS (oral rehydration solution) should be given in small, frequent amounts. Continue breastfeeding or formula feeding for infants.
• Fluid intake: Encourage fluids such as water or diluted juice to prevent dehydration.
• Continue normal diet: Once vomiting subsides, continue feeding the child their regular diet. Avoid fatty or sugary foods.

Second-line Treatment:

• Antibiotics: Generally not recommended for viral gastroenteritis. Antibiotics may be used for certain bacterial infections (e.g., Shigella, Campylobacter) based on stool culture results.
• Antiemetics: Ondansetron may be considered for children with persistent vomiting.

Hospital Referral:

• Children with severe dehydration or unable to tolerate oral fluids should be referred for intravenous rehydration.
• Consider referral if there is bloody diarrhoea, high fever, or suspected complications such as intussusception.

References

1. NHS (2023). Gastroenteritis in Children. Available at: NHS
2. NICE (2024). Gastroenteritis in Children: Diagnosis and Management. Available at: NICE Guidance
3. British Medical Journal (2023). Management of Gastroenteritis in Children. Available at: BMJ