Messy, smelly and non-stop—Jane Austen would have described it as a continual state of inelegance. Delhi’s biggest embarrassment, it is now also the title of a Bollywood film. The phrase Delhi Belly, according to the Hanklyn-Janklin dictionary, is “a stomach disorder sometimes afflicting newcomers to the capital". Infectious amoebic agents such as Entamoeba histolytica enter the body, the intestine reacts and throws out all infection through frequent motions.

It’s not Al Qaeda, but Americans take Delhi Belly seriously. According to a US diplomat who spoke on condition of anonymity since he is not authorized to share this information, his embassy in New Delhi maintains a laboratory devoted to testing for germs and diseases such as Delhi Belly. Embassy staff often arrive at the office carrying small brown bags that have jars with “poop" samples to be tested at the lab.

Delhi Belly is not the world’s only “traveller’s diarrhoea". There’s a limerick to be composed from the colourfully named loosies that dot the world’s tourist traps: Turkey trots, Montezuma’s revenge, Casablanca crud, Malta dog, Singapore shakes, Aden gut, Gyppy tummy, Rangoon runs, Kathmandu quickstep, Greek gallop, Hong Kong dogs and Trotsky’s. Strangely, it is Delhi that has captured the global imagination when it comes to vomit, runs and cramps. There are actually limericks on Delhi Belly (see Word play).

The food bug: (clockwise from top) Foreign tourists walk through Paharganj’s main bazaar; a tourist sups on an Indian thali at a Paharganj eatery; people enjoying momos from a street cart; and Canadian tourist Bryce buying a plate of aloo-chaat in Paharganj.

“The perils of Delhi Belly are exaggerated," says Ranjana Sengupta, the author of Delhi Metropolitan. “For purely fortuitous alliterative reasons, Delhi has been awarded this undeserved reputation. An E. coli outbreak has occurred in Germany. Will future guidebooks carry dark warnings about Berlin Belly? I doubt it."

There is no record of the phrase’s first appearance. The section on diseases in A Gazetteer of Delhi 1883-84 mentions Delhi Boil, not Delhi Belly. “The term first appeared in the summer of 1857," claims R.V. Smith, author of several books on the city. “The Indian mutineers had taken over the capital and the British were encamped on the Ridge where many of them were incapacitated due to upset tummies. It was they who coined the term Delhi Belly."

Some 114 years later, then US president Richard Nixon’s national security adviser Henry Kissinger made his career’s great diplomatic gamble, with some help from Delhi’s infamous syndrome. In 1971, he went to Islamabad, where he pretended to be down with Delhi Belly that required him to recover at a Pakistani resort. In truth, he secretly flew to meet Chinese leaders in Beijing, paving the way for Nixon’s historic summit with Mao Zedong.

Then, 31 years later, American journalist Jason Overdorf moved to Delhi and started a blog called… well, guess (incidentally, the phrase was the first choice for the name of this city column too). “The name for the blog came from my wife. We thought was catchy and would also give us licence to whine about the city," says the man who has been attacked by Delhi Belly more than 20 times.

“Delhi Belly is dead," says Delhi-based Prof. Pushpesh Pant, author of India: The Cookbook. “Now our hygiene standards are high, bottled water is available everywhere, dhabas cater to foreigners and many eateries serve gol gappas with mineral water. The Delhi Belly scaremongers are the types who dine at five-star hotels and who like to run down India, which is now a powerhouse economy."

In his four years as the Delhi-based Asia correspondent of The Independent, Andrew Buncombe has frequently reported on India’s booming economy. A week ago he had his latest and most serious attack of Delhi Belly. “After 6 hours of shit and vomit, I was having muscular spasms in my leg and had to be admitted to a hospital where I was given IV (intravenous) drips," he says.

The attack is not confined to foreigners. “I get 40 cases of Delhi Belly each month, both Indians and foreigners," says Sanjiv Zutshi, a physician who has two clinics in Nizamuddin East. “Carelessness about picking your food is one reason and the other factor, which is common for foreigners, is that their stomachs are not used to Indian spices and sometimes their intestines react by causing loose motions."

For most Delhi Belly survivors, memories of the first attack are as clear as if it had happened last night. “I first had Delhi Belly in the bathroom of the Ambassador Hotel after drinking a delicious lassi near Khanna (Talkies) cinema in Paharganj in high summer," says South African designer Marina Bang, who has been living in the city for two years. James Baer, a freelance writer from London, who has lived in Delhi for two and a half years, suffered from Delhi Belly thrice during the first six months. “Once was after eating a burger at a five-star hotel," says Baer. “I was in bed for two days, feverish and cramping, almost unable to move with the pain." Ron Lussier, a San Francisco-based photographer, visited India early this year and caught the “inevitable rumblings" of Delhi Belly, 250km away in Jaipur. “It happened after trying gol gappas," says Lussier.

Is there any way to remain forever a Delhi Belly virgin?

“I recommend avoiding meat and especially pork during high summer. Even in the most hygienic kitchens, a failed fridge can reduce meat to a hotbed of bacteria," says Bang. “The trick is not to search for the so-called authentic food in the grubby eateries of Old Delhi," says Prof. Pant. “Have piping hot dal, tandoori roti and uncut vegetables and you will never have Delhi Belly," promises Dr Zutshi.

The foreign backpackers in Paharganj, popular for its cheap hotels, cafés and bakeries that have shelves stacked with tattered Lonely Planet guides and toilet paper rolls, have a Hindu-like fatalism about Delhi Belly. “It’s inevitable," says Canadian tourist Bryce, popping in fried aloo wedges he has purchased from a roadside cart. “I eat everything. If you hide from germs and bugs, of course you’ll fall sick. Your body needs to get used to all this," he says, waving his arm at the open drains, the urinating cow, the hanging wires, the half-naked beggars and the fly-ridden aloo-chaat cart. That’s perhaps the best survival tip.