Diarrhea means having more than three bowel movements in a 24 hour period where the stool is loose or watery. a loose stool being one that would take the shape of a container. Gastroenterologists define diarrhea as the passage of more than 200g stool daily.


It is classified as:

  1. Acute watery diarrhea: Lasting for hours or days.
  2. Persistent diarrhea: Lasting for 14 days or longer and sometimes for months.
  3. Dysentery: presence of visible blood in stool.
  4. Chronic diarrhea or Relapsing diarrhea: It occurs in irritable bowel syndrome.


There are some causative agents as well as various other factors responsible for Diarrhea.

Causative agents are:

  1. Viruses:

a) Rota virus

b) Astro virus

c) Adeno virus

d) Calci virus

e) Corona virus

f) Entero virus

  1. Bacteria:

a) Campylobacter jejuni

b) Escherichia coli

c) Shigella

d) Salmonella

e) Vibrio cholerae

f) Vibrio parahaemolyticus

g) Bacillus cereus

  1. Others:

a) Entamoeba histolytica

b) Giardia Intestinalis

c) Trichuria

d) Cryptosporidium SPP

e) Intestinal worms

Reservoir of Infection

  • For some enteric pathogens, human are the principle reservoir and thus most transmission originates from human factors ( such as enterotoxigenic E. coli, shigella spp., V. cholerae, Giardia lamblia and E. histolytica.).
  • For other enteric pathogens, animals are important reservoirs and transmission originates from both human and animal faeces (such as Campylobacter jejuni, Salmonella spp. and Y. enterocolitica).
  • For viral agents of Diarrhea, the role of animal reservoirs in human disease remains uncertain.

Some factors responsible for Diarrhea are:

  • Poor personal hygiene, Inappropriate excreta disposal
  • Environmental Factors (frequent in warm season)
  • Contaminated food and drinks.
  • Some associated diseases (Malabsorption Syndrome, Irritable bowel syndrome, Protein energy malnutrition)

Mode of Transmission

Most of the pathogenic organisms of diarrhoeal diseases are transmitted primarily or exclusively by the faecal-oral route. This transmission may be water-borne, food-borne or direct transmission via fingers, fomites or dirt which may be ingested by young children.

Control of Diarrhoeal Disease

The intervention measures recommended by WHO may be classified as below:

  1. Short Term

a) Appropriate Clinical Management

  1. Long Term

a) Better MCH care practices

b) Preventive strategies

c) Preventing diarrhoeal epidemics.

Appropriate Clinical Management:

  1. Oral rehydration therapy
  2. Appropriate feeding
  3. Chemotherapy

Better MCH care practices

  1. Maternal Nutrition
  2. Child Nutrition

Preventive Strategies

  1. Sanitation
  2. Health education
  3. Immunization
  4. Fly control.