Diarrhoe

• Diarrhoea


  A symptom, and not a disease per se, of GIT illness which can occur as a result of a variety of pathologic or non-pathologic conditions
• When consuming typical western diet, infants pass about 10ml/kg/24hrs and adults up to 200g/24hrs of stool
• It is not easy to define a normal stool pattern in an individual because the frequency & consistency of stools can vary depending on the diet & other factors
• Frequency of stool in breast-fed infants can range from multiple stools daily to one bowel movements in a week and still be considered within normal range
• Operative definition of diarrhoea

  Passing of >3 liquid stools in a 24hr period
• Diarrhoea


  Passing of >10ml/kg/day or 299g/day for an older child
• The terms chronic, persistent and protracted diarrhoea are often times used interchangeably
• Chronic diarrhoea


  Passing four or more watery stools per day for a period of 2weeks or more
• Diarrhoeal diseases are the 2nd leading cause of mortality worldwide in children younger than 5 years of age (760,000 deaths/year) (WHO media news April 2013)
• In the US, <5yrs children have more than 20million episodes of diarrhea each year leading to 200,000 hospitalizations
• Water and solutes are absorbed in the intestine

  1. Na+ coupled solute transport

  2. Na+/H+ exchanges

  3. Paracellular transport
• In acute diarrhoea Na+/H+ exchangers and paracellular transport remains intact even with viral enteritis associated with epithelial damage
• Secretory functions of the small intestine

  Mainly dependent on chloride secretion
• The negatively charged Cl- in the intestinal lumen causes net passive transfer of Na+ and water to the lumen and hence increased fluid and ion loss
• Intestinal absorption occur @ the villi while secretion occur @ the crypts
• In the colon, net excretion of H+ and HCO3- and net absorption of Na+ occurs through HCO3- and Na+/H+ exchangers
• The journey of food from mouth to anus involves many complex steps, reflecting the integrated functions of different organs
• Any internal or external factor affecting the above mentioned organs and processes can alter stool consistency or frequency and cause diarrhoea
• Classification of Diarrhoea


  • Acute vs chronic according to duration
  • Secretory, osmotic, inflammatory and fatty diarrhoea
• Causes of Acute Diarrhoea

  • Infectious aetiologies (Viral, Bacterial, Parasitic)
  • Non-infectious causes (Drug induced, Food allergies, Extra-intestinal infections, Surgical conditions)
• Acute diarrhoea


  • Usually benign, self limiting and resolves in a few days without any intervention
  • Can be watery or invasive (bloody) in nature
• Accompanying fever and vomiting increase the risk of dehydration
• During acute diarrhoea, young infants are at much greater risk of dehydration compared to older children
• Children with moderate to severe malnutrition are at higher risk of developing post enteritis syndrome due to malnutrition-induced immunodeficiency or altered intestinal permeability
• Stool Na+ can be as high as 90mmol/l in Cholera and 40 to 60mmol/l in Rotavirus diarrhoea
• Stool should be sent for culture when there is a suspicion for Salmonella, Shigella, E. coli or Campylobacter based on the history
• Stool should be checked for ova and parasites when there is a suspicion for parasitic infestation such as history of travel in endemic areas, swimming in lakes, camping or other predisposing factors
• There is no evidence-based role for anti-motility agents in management of acute diarrhoea in children
• WHO guidelines for assessment of dehydration in a patient with diarrhoea


  • None (<5%)
  • Some dehydration (5-10%)
  • Severe dehydration (> 10%)
• Important Historical Information in a Child with Diarrhoea

  • Duration of diarrhoea
  • Onset of diarrhoea
  • Number of daily stools
  • Volume of stools
  • Consistency of stools
  • Presence of blood in stool
  • History of recurrent bacterial infection or immunosuppressive state
  • Painful defecation or not
  • Faecal urgency
  • Presence of diarrhoea in the fasting state and while sleeping
  • Associated symptoms
  • Dietary intake
  • History of recent antibiotic usage
  • History of recent travel/camping
  • History of previous surgery
• Physical Examination in the Patient with Diarrhoea

  • Degree of dehydration
  • Signs of systemic illness
  • Signs of significant dehydration
  • Current weight and pre-morbid weight
  • Assessment of growth chart
  • Presence of pallor, icterus, petechia, skin rash
  • Abdominal tenderness, distended abdomen
  • Rectal examination
  • Extra intestinal manifestations
• Differential Diagnoses of Chronic Diarrhoea in Children

  • Malabsorptive Diarrhoeas (Carbohydrate Malabsorption, Fat Malabsorption)
  • Chronic diarrhoea of inflammatory origin (IBD, Coeliac disease, Collagenous colitis, Eosinophilic gastroenteritis)
  • Congenital diarrhoeas
  • Intestinal Failure
  • Infections
  • Medication Induced
• n secondary to NEC, Crohn's ileitis, congenital absence of ileal bile receptor

  Causes of chronic diarrhoea of inflammatory origin
• Chronic diarrhoea of inflammatory origin

  • Inflammatory bowel disease (IBD) – Crohn's dx, ulcerative colitis, indeterminate colitis
  • Coeliac disease
  • Collagenous colitis
  • Eosinophilic gastroenteritis
• Congenital diarrhoeas


  • Microvillous inclusion diarrhoea
  • Tufting enteropathy
  • Sodium channel diarrhoea
  • Congenital glucose – galactose malabsorption
  • Abetalipoproteinemia and hypobetalipoproteinemia
  • Congenital lactase deficiency
• Causes of Intestinal Failure

  • Extensive intestinal resection (NEC, volvulus, infarction, ischemia, CD)
  • Motility issues (chronic intestinal pseudo-obstruction, (CIPO)
  • Small bowel bacterial overgrowth
• Infections causing chronic diarrhoea

  • Chronic parasitic infestations (Giardia lamblia, Cryptosporidium)
  • Viral infections (HIV)
  • Bacterial: Clostridium difficile, Salmonella, Campylobacter, Post-enteritis syndrome
• Medication Induced causes of chronic diarrhoea

  • Chronic laxative abuse (PEG 3350, lactulose)
  • Magnesium containing antacids
  • Antibiotic induced diarrhoea
• Neurohormonal causes of chronic diarrhoea

  • Hyperthyroidism
  • Neuroblastoma
  • Gastrinoma
  • VIPoma
  • APUDOMA
  • Ganglioneuroma
• Other causes of chronic diarrhoea


  • Imitable bowel syndrome
  • Faecal Impaction with overflow incontinence