84 Diarrhoea Diseases
84.1 Introduction
Diarrhoeal diseases remain one of the most common causes of morbidity and mortality among children worldwide, particularly in low- and middle-income countries. In sub-Saharan Africa, including Ghana, diarrhoea is a leading cause of outpatient visits, hospital admissions, and deaths among children under five years. The World Health Organization (WHO) estimates that children under five experience an average of three episodes of diarrhoea per year, contributing to significant nutritional deficits and growth faltering.
Definition: Diarrhoea is defined as the passage of three or more loose or watery stools within 24 hours, or a stool consistency that is looser than normal for the individual. In infants on breast milk, frequent passage of soft stools may be normal and should not be mistaken for diarrhoea unless the stools are unusually watery and accompanied by other symptoms such as dehydration or fever.
84.2 Classification
Diarrhoeal diseases are broadly classified based on duration and pathophysiology.
84.2.1 By Duration
- Acute Diarrhoea: Lasts less than 14 days. Usually due to infectious causes (viral, bacterial, or parasitic).
- Persistent Diarrhoea: Lasts 14 days or longer. May follow an acute infectious episode and often associated with malnutrition, secondary lactose intolerance, or underlying enteric pathology.
- Chronic Diarrhoea: Lasts more than 30 days. Typically due to non-infectious causes such as malabsorption, inflammatory bowel disease, or congenital disorders.
84.2.2 By Clinical Presentation
- Acute Watery Diarrhoea: Sudden onset, stools watery without visible blood. Common causes: Rotavirus, Norovirus, Vibrio cholerae, ETEC.
- Acute Bloody Diarrhoea (Dysentery): Presence of visible blood or mucus; indicates mucosal invasion. Common causes: Shigella, Entamoeba histolytica, Salmonella, Campylobacter.
- Persistent Diarrhoea: Often due to prolonged infection, malnutrition, or mucosal damage.
- Diarrhoea with Severe Malnutrition: Often chronic and complicated by electrolyte imbalance and secondary infections.
84.3 Epidemiology
In Ghana, diarrhoeal diseases are among the top five causes of outpatient visits in children under five. Peak incidence is between 6 months and 2 years (weaning period). Seasonality is common — cases often increase during the rainy season due to contamination of water sources. Contributing factors include poor sanitation, inadequate hand hygiene, unsafe drinking water, and improper food handling.
84.4 Aetiology
84.4.1 Infectious Causes
84.4.1.2 Bacterial
- ETEC (Enterotoxigenic E. coli): Common in travellers and children; toxin-mediated secretory diarrhoea.
- EPEC (Enteropathogenic E. coli): Infantile diarrhoea.
- Shigella spp.: Dysentery with fever, tenesmus, bloody stools.
- Salmonella (non-typhoidal): Food-borne; may cause invasive disease in infants.
- Campylobacter jejuni: Associated with poultry; can be dysenteric.
- Vibrio cholerae: Causes profuse watery diarrhoea (“rice-water stools”).
- Clostridioides difficile: Often post-antibiotic.
84.4.1.3 Parasitic
- Giardia lamblia: Chronic/intermittent diarrhoea, malabsorption, steatorrhoea.
- Entamoeba histolytica: Amoebic dysentery; may complicate with liver abscess.
- Cryptosporidium parvum: Important in immunocompromised children (e.g., HIV).
- Isospora belli, Cyclospora: Prolonged diarrhoea in immunosuppressed patients.
84.4.2 Non-infectious Causes
- Food intolerances (e.g., lactose intolerance)
- Celiac disease
- Inflammatory bowel disease (IBD)
- Irritable bowel syndrome (IBS)
- Congenital enzyme deficiencies
- Medications (antibiotics, laxatives)
84.5 Pathophysiology
Diarrhoea results from disturbed intestinal fluid and electrolyte transport. Key mechanisms:
- Osmotic diarrhoea: Non-absorbable solutes in the lumen draw water (e.g., lactose intolerance). Typically stops with fasting.
- Secretory diarrhoea: Increased electrolyte and water secretion (e.g., cholera, ETEC). Persists despite fasting.
- Exudative diarrhoea: Mucosal inflammation causes loss of blood, mucus, and proteins (e.g., Shigella, E. histolytica).
- Motility-related diarrhoea: Rapid transit reduces absorption time (e.g., post-surgical states).
- Mixed mechanisms: Especially in persistent diarrhoea where infection and malnutrition combine.
84.6 Clinical Features
84.6.1 Symptoms
- Frequent loose or watery stools (± blood)
- Vomiting (common in viral aetiologies)
- Fever
- Abdominal cramps or pain
- Tenesmus (with dysentery)
- Reduced appetite
- Signs of dehydration: thirst, dry mucous membranes, decreased urine output, sunken eyes
84.6.2 Signs of Dehydration (WHO classification)
- No dehydration: alert, normal eyes, drinks normally, skin pinch goes back quickly.
- Some dehydration: restless/irritable, sunken eyes, thirsty, skin pinch goes back slowly.
- Severe dehydration: lethargic/unconscious, very sunken eyes, unable to drink, skin pinch goes back very slowly (>2 seconds).
84.7 Assessment and Diagnosis
84.7.1 History
- Onset, duration, stool frequency/character, presence of blood or mucus
- Associated vomiting, fever, abdominal pain
- Recent antibiotic use, recent food or water exposures, sick contacts
- Breastfeeding/weaning history
- Immunization status (rotavirus vaccine)
- Underlying conditions (HIV, malnutrition)
84.7.2 Physical Examination
- Vital signs, hydration assessment (capillary refill, pulse, blood pressure if indicated)
- Weight and comparison with prior measurements
- Nutritional assessment for wasting/edema
- Abdominal examination for tenderness, distension, palpable masses
- Perianal and perineal inspection for skin irritation or lesions
84.7.3 Laboratory Investigations
(Not required for uncomplicated mild diarrhoea)
- Stool microscopy, culture and sensitivity: Indicated for persistent diarrhoea, dysentery, or outbreak investigation.
- Stool ova and parasites: If parasitic infection suspected.
- Stool for reducing substances: If lactose intolerance/malabsorption suspected.
- Electrolytes and renal function: In severe dehydration or when IV fluids are given.
- HIV testing: For chronic/persistent diarrhoea or risk factors.
84.8 Differential Diagnosis
- Acute appendicitis (may present with diarrhoea early)
- Urinary tract infection presenting with fever and diarrhoea
- Intussusception (bloody stools, abdominal pain, vomiting)
- Malabsorption syndromes
- Irritable bowel syndrome
- Systemic sepsis with diarrhoea
84.9 Management
84.9.1 General Principles
- Assess and correct dehydration.
- Maintain nutrition and early refeeding.
- Treat specific causes when indicated.
- Prevent complications and recurrence.
84.9.2 WHO Fluid Management Plans
- Plan A (No dehydration): Home care with extra fluids and continued feeding.
- Plan B (Some dehydration): ORS 75 mL/kg over 4 hours.
- Plan C (Severe dehydration): Immediate IV rehydration (Ringer’s lactate or normal saline).
84.9.2.1 Plan A — No Dehydration
- Continue breastfeeding and normal feeding. Provide extra fluids:
- Less than 2 years: 50–100 mL after each loose stool
- 2–10 years: 100–200 mL after each loose stool
- Less than 10 years: as much as desired
- Give zinc supplementation (10 mg/day if <6 months; 20 mg/day if ≥6 months) for 10–14 days.
- Educate caregivers about danger signs.
84.9.2.2 Plan B — Some Dehydration
- Give ORS 75 mL/kg over 4 hours and reassess. If improved, continue feeding; if not, repeat Plan B or escalate to Plan C.
- Continue breastfeeding and frequent small feeds.
84.9.2.3 Plan C — Severe Dehydration
- IV fluid therapy:
- Infants (<12 months): 30 mL/kg in first 1 hour, then 70 mL/kg over next 5 hours (Ringer’s lactate preferred).
- Children (>12 months): 30 mL/kg in first 30 minutes, then 70 mL/kg over next 2.5 hours.
- Monitor for signs of fluid overload; reassess frequently.
- If IV access cannot be established, use nasogastric rehydration with ORS.
84.9.3 Nutritional Management
- Continue breastfeeding throughout the illness.
- Do not withhold food; resume age-appropriate feeding as soon as rehydration is achieved.
- Use energy-dense, micronutrient-rich foods during recovery and give extra meals for 2 weeks post-illness.
- Avoid high-sugar drinks and undiluted fruit juices.
84.9.4 Specific Therapy
- Antibiotics are not routine for acute watery diarrhoea. Indications include:
- Dysentery (suspected Shigella)
- Confirmed cholera with severe dehydration
- Laboratory-confirmed bacterial infections
- Immunocompromised patients with invasive bacterial disease
Common choices (local guidelines may vary): - Shigella: Ciprofloxacin 15 mg/kg orally twice daily for 3 days (check local resistance patterns). - Cholera: Single dose doxycycline (adults/older children) or azithromycin 10 mg/kg single dose where doxycycline contraindicated. - Giardiasis/Amebiasis: Metronidazole (observe paediatric dosing recommendations).
Avoid antimotility agents (e.g., loperamide) in young children.
84.9.5 Zinc Supplementation
- Reduces severity and duration, and prevents recurrence. Dose:
- <6 months: 10 mg/day for 10–14 days
- ≥6 months: 20 mg/day for 10–14 days
84.10 Management of Persistent and Chronic Diarrhoea
- Investigate and treat underlying causes: persistent infection, malabsorption, cow’s milk protein allergy, post-infectious lactose intolerance.
- Nutritional rehabilitation with low-lactose or lactose-free feeds if indicated.
- Replace micronutrients (zinc, vitamin A, folate) and correct anaemia when present.
- Consider referral for specialised investigations (endoscopy, biopsy, sweat test, advanced imaging) if diarrhoea persists beyond 4 weeks.
84.11 Complications
- Dehydration and hypovolaemic shock
- Electrolyte disturbances (hypokalaemia, hyponatraemia)
- Metabolic acidosis
- Malnutrition and stunting
- Secondary lactose intolerance
- Acute kidney injury in severe cases
- Sepsis, especially with invasive bacterial pathogens
84.12 Prevention and Control
84.12.1 Household measures
- Exclusive breastfeeding for the first 6 months of life
- Handwashing with soap after defecation and before food preparation
- Safe drinking water (boiling, chlorination, filtration)
- Proper sanitation and safe disposal of faeces
- Hygienic food preparation and storage
- Timely use of ORS and zinc in episodes of diarrhoea
84.12.2 Public health measures
- Rotavirus vaccination included in Ghana’s EPI since 2012 — major impact on severe rotaviral disease.
- Cholera surveillance and targeted vaccination in outbreaks and endemic areas.
- Strengthening WASH (Water, Sanitation and Hygiene) infrastructure and behaviour-change programmes.
84.13 Prognosis
Most children recover fully with early recognition and appropriate management. Recurrent or persistent diarrhoea is a major contributor to malnutrition, stunting, and impaired cognitive development.
84.14 Key Clinical Points
- Accurate assessment of dehydration is critical and guides management.
- ORS and zinc are cornerstone therapies for most childhood diarrhoeas.
- Continue feeding and especially breastfeeding; do not withhold nutrition.
- Reserve antibiotics for indicated cases and follow local resistance patterns.
- Prevention through vaccination (rotavirus), breastfeeding, and WASH interventions is essential.
84.15 Suggested Further Reading
- World Health Organization. Pocket Book of Hospital Care for Children, 3rd Edition (most recent).
- Ghana Health Service. Standard Treatment Guidelines (latest edition).
- UNICEF/WHO. Integrated Management of Childhood Illness (IMCI) Chart Booklet.