• Passage of ≥3 loose or watery bowel motions in 24 hours. Without blood: enteritis, with blood (dysentery) Chronic if >14 days (?28).

• Top 10 cause of death globally, #2 in low-income countries

• >1.7 billion episodes per year (c/w 120 million pneumonia), 36 million severe

• 700,000 deaths (c/w 1.3 million pneumonia), 72% in the first 2 years of life

Pathogens

• Virus: Rotavirus, adenovirus, astrovirus, coronavirus...

• Bacteria: E.Coli (EIEC, EHEC, ETEC, EAggEC, EPEC), campylobacter spp., Shigella spp., clostridium difficile, salmonella spp, bacillus cereus, cholera

• Protozoa: Entamoeba histolytica, giardia intestinalis, cryptosporidium, balantidium coli, isospora belli, cyclospora, microsporidiosis....

• Helminths: Nematodes (hookworm, trichuris (whipworm), ascaris, strongyloides); trematodes (schistosoma spp.)

Non-infectious

• GI tract: Diverticulitis, inflammatory bowel disease, cancer, constipation overflow, pelvic inflammatory disease

• Metabolic: Diabetes, pancreas tumour, carcinoid syndrome, uraemia

• Generalised illness: Malaria, sepsis (inc. meningococcal), pneumonia

• Drugs: NSAIDS, cytotoxics, antibiotics

Most attributable pathogens

Global Enteric Multicentre Study (GEMS): prospective matched case-control study. 5,304 episodes (77% watery, 23% dysentery)

• 0-11 months: rotavirus, cryptosporidium, E.coli, shigella, adenovirus

• 12-22 months: rotavirus, shigella, cryptosporidium, E.coli, aeromonas

• 24-59 months: shigella, rotavirus, campylobacter, cholera, E.coli

Food poisoning

Traveller's diarrhoea

Assessment

• Clinical classification

• Investigations

Management

• Oral rehydration salts mainstay of treatment

• Zinc

• Nutrition

• Rotavirus

• Specific antimicrobials to be considered for Shigella, Cholera, Giardia, Entamoeba histolytica, travellers diarrhoea....