C.difficile

• JAMA review (2009): http://jama.ama-assn.org/cgi/reprint/301/9/954.pdf;
  

GI bleed

• Scottish Guidelines: summary: http://www.sign.ac.uk/pdf/qrg105.pdf;
• IV PPI (bolus + infusion) before endoscopy: NEJM(2007): http://www.ncbi.nlm.nih.gov/pubmed/17442905;

Traveller's diarrhoea:

• Bact:
• E coli (enteropathogenic: EPEC, enterotoxigenic: ETEC, enteroaggregative: EAEC; enteroinvasive EIEC; enterohaemorrhagic EHEC)
• Campylobacter
• Aeromonas
• Shigella
• Salmonella
• Vibrio (cholerae) in epidemics; Vibrio parahaemolyticus in seafood poisoning
• HIV: Mycobacterium avium
• Viral: 30-40% in affluent countries
• Rotavirus
• Norovirus
• enteric adenoviruses
• CMV (eg HIV)
• Parasitic:
• Giardia lamblia (eg HIV)
• Cryptosporidium parvum (eg HIV)
• Cyclospora cayetanensis (eg HIV)
• [non-pathogenic isolates: Entamoeba coli, Endolimax nana, lodamoeba butschlii, Blastocystis hominis] 
• HIV: also Isospora belli, Entamoeba histolytica