AAD or Antibiotic-associated Diarrhoea: Occurs when antibiotics disturb the natural balance of “good” and “bad” bacteria in your intestinal tract, causing harmful bacteria to proliferate far beyond their normal numbers.

Vancomycin: Vancomycin is an antibiotic used in the prophylaxis and treatment of infections caused by Gram-positive bacteria. It is often reserved as the “drug of last resort”, used only after treatment with other antibiotics had failed.

Metronidazole: Metronidazole is a nitroimidazole antibiotic drug used in the treatment of infections caused by susceptible organisms particularly anaerobic bacteria and protozoa.

Pseudomembranous colitis or PMC: An infection of the colon caused by the bacterium Clostridium difficile. In most cases, a pateient presenting with pseodomembranous colitis has recently been on antibiotics.

Tolevamer: A possible non-antibiotic treatment for Clostridium difficile currently undergoing trials by US biotech company Genzyme.

Gut Flora: Gut flora, or intestinal bacteria, are the bacteria that normally live in the digestive tract and perform a number of useful functions involving digestion for their hosts.

Anaerobic organism: An anaerobic organism or anaerobe is any organism that does not require oxygen for growth.

Commensalism: In ecology, commensalism is an interaction between two living organisms, where one organism benefits and the other is not affected. As with all ecological interactions, commensalisms vary in strength and duration from intimate, long-lived symbioses to brief, weak interactions through intermediaries.

Enterotoxin: An Enterotoxin is a toxin released by a micro-organism in the Lower Intestine. The enterotoxin alters the permeability of the intestinal wall. This causes water and electrolytes to leak into the intestinal tract , causing diarrhoea.

Cytotoxins: are substances that mark a characteristic cytotoxicity; that is, are toxic to cells.

CDAD: Clostridium difficile Associated Diarrhoea.

CDAT: Climate Data Analysis Tool.