For millions of Britons it is a secret they dare not discuss. A problem they put up with, silently, often for decades. Incontinence will affect 40 per cent of women, and one in ten men at some point in their lives. And it’s not simply an embarrassing inconvenience: it can leave sufferers near-housebound for fear of having ‘an accident’. Others are forced to shell out hundreds of pounds on special pads and underwear to get through their lives. Sheila Cakebread, 73, from Godalming, Surrey discovered several of her friends were being treated with Botox for years for their incontinence, to great effect