Green’s Dictionary of Slang

food poisoning, epitomized by diarrhoea suffered by tourists in India.

1944		Newsweek 28 Feb. 76/1: Joe was off again [...] to be the first to hit the heat and filth of India [...] He got ‘Delhi belly’ (a form of dysentery).
1955		Wash. Post and Times Herald 24 July F17: Anyone suffering from art-gallery gout, Delhi belly, jaded eyeballs or other ills of the traveler on the high road, is hereby advised to relax while suffering. Help is on the way.
1960		Wash. Post and Times Herald 10 Apr. L6: The disorder occurs often in Mexico and has been nicknamed Montzuma’s revenge [...] In Italy, Turkey, Egypt and India it is named Turkey trot, gippy tummy, and Delhi belly.
1972		Time 22 May 104: South of the border, it is turista or ‘the Aztec two-step’. In Asia, visitors from the West call it ‘Delhi belly’.
1984–5		Maledicta VIII 99: New Delhi belly also relates intestinal infirmity with oriental travel.
1991		D. Jarman letter 5 June Smiling in Slow Motion (2000) 14: Ken has an upset stomach that he calls Delhi Belly.
2000		eve Sept. 64: Followed by [...] a bout of severe Delhi-belly in India.
2011		Talk Radio 702 on Cape Radio 2 Mar. [radio] The Guptas should get a taste of Delhi belly.