The first half of the ad, which was shot at a primary school in Hackney, shows British children smiling and giggling as they sing the words "When it comes out your bum like a bullet from a gun. Diarrhoea. Diarrhoea."
The second half of the ad cuts to a child in Zambia, who speaks the following words in a contrastingly sombre tone of voice: "When it’s just killed your sister and you’re really going to miss her. Diarrhoea. Diarrhoea."
The ad then asks viewers to text "dig" to 88008, or call 0800 088 7088, or visit the campaign microsite.
The advertising, which will run until the end of September, is targeted at 35 to 50-year-old professionals, to encourage them to sign up to donate regularly to WaterAid.
The campaign also asks people to sign a petition that calls on the Government to support a drive to provide more toilets in the world’s poorest countries.
The overarching campaign is underpinned by the line "Dig toilets, not graves" and aims to show how providing proper sanitation in the form of pit toilets can help stop the spread of diarrhoea, which kills 4,000 children every day in developing countries.
Amy Faulkner, WaterAid’s supporter recruitment team manager, said: "We are confident that the campaign will help us to achieve our fundraising targets for this year, as well as getting the critical issues of sanitation and diarrhoea talked about more widely."
The ad is being broadcast on channels including Sky One, Living, Discovery, Bravo, More 4 and Sky Sports. Supporting activity will include inserts, email, a viral ad and online display.