It's Getting a bit stressful, watching TV these days. Take Hollywood Lovers, for instance. You slump down in front the telly and before can say "film star" there's female genital enlargement and all sorts of close- up unpleasantness on the screen. No sooner have you recovered, than it's into the normally safe ad break where you find two ads for two different kinds of thrush treatment. Honestly.

The first one of these, for Diflucan, was notable for its breezy cheerfulness in a sector that is normally characterised by a certain gentle tact. Indeed, whenever the British advertiser is forced to sell you a product that has some function down there, they seem more embarrassed about it than we do. The old sanitary protection gang had a bash at breaking taboos with the earnest, late 1980s "It's My Life" commercial for Tampax, starring all manner of roller skating lovelies, but it couldn't last. Now we have Always Nightime, where satin sheets, some soft focus camera work and a hushed voice talking euphemistically of "nightime worries" tell us all that we need to know.

With Diflucan - which is testing its advertising in London, gentle reader, before distributing it to a grateful nation - a busy woman who lives life to the max rushes into a restaurant whilst administering her Thrush treatment. (No, don't worry. The point about Diflucan is that it is administered orally. In pill form.) She then sits down with her good friend for a nice gossip over lunch. In a concession to years of advertising tradition, the product message is delivered in subtitle form which Diflucan's ad agency, Integrator, believes is crucial.

"No one wants to hear the word thrush shouted out of the screen at them," says Sara Sorby, account director on Diflucan at Integrator. "We wanted the commercial to be positive and up beat but we didn't want to alienate anyone." Diflucan is a new product in the UK's pounds 18 million thrush treatmeant market and it is advertising on TV for the first time. This has flushed its rival and current market leader Canesten out of the woodwork and it is now on TV with a rival ad. Canesten is an altogether more matronly ad, although faces the same problem as sanitary wear in that it is forbidden to even gently zoom in on a clothed shot of the affected area.

Patrick Johnson is the director of consumer care at Canesten's parent company Bayer. He dismisses the Diflucan work with a sneer and refutes claims that Diflucan's work has prompted his latest ad campaign. "I would rather say that Diflucan is responding to our success," he huffs. "We have a 90 per cent market share and we've been around for 25 years. Diflucan is running all these aspirational ads featuring glamorous women in expensive restaurants while our consumer research shows women just want honest, straightforward advertising."

It's clearly getting personal between Bayer and Diflucan's parent, Pfizer Consumer Health, so it looks like there's a Pepsi-v-Coke-style thrush war on the way. Already the statistics are being distorted with Canesten claiming a 90 per cent market share and Diflucan claiming a 30 per cent share. The first casualty of war is always truth. In fact, according to Harriet Green, a journalist on adland bible Campaign, Canesten and Diflucan are both as bad as each other.

"This kind of advertising is always irritating," she says. "There's no humour to it, it's desperately coy and it doesn't really get to the heart of the matter. It just leaves people confused. They have no idea what's going on, whether they need the treatment or what the benefits of this treatment over that treatment are. It's OK having that consumer crisis over a fizzy drink, but thrush is a painful condition for many women and they deserve to be treated with more respect."

TV viewers should expect the war to hot up. If the trial in London is successful, Diflucan ads will be appearing all over the country and Canesten ads will never be far away from them. It's enough to give you a pain in the bum. Or, as the Americans say, fanny.