was going through biology past papers and this question baffled me

'Cholera bacteria priduce a toxin which causes the epithelial cells of the intestine to secrete chloride ions into the lumen of the intestine. explain why diarrhoea is a symptom of choler?'

the question is a three marker, so i guess, it'll want three points, but i have no idea what it is going on about,

anyone have any clue?

Just to extend on the above answers (and to make sure you get all the points you possibly can), the cholera toxin binds to receptors that upregulate the action of adenylate cyclase in the cell, which therefore increases cAMP production. this acts on the chloride channels in the cell, increasing the Cl- efflux into the lumen. this is what causes the massive amount of water to enter the lumen. this diagram ebi.ac.uk/interpro/potm/2005_… explains it better than me.

bacteria secrete a toxin, chloeragen, which disrupts the funtion of the epithelium causing salts and water to leave the blood. THis lack of salt nd water causes Diarrhoea