Green’s Dictionary of Slang

wherry-go-nimble n.

diarrhoea.

1821		Countess of Glengall report 5 Sept. in Gore Creevey’s Life and Times (1934) 144: [T]he whole of the inhabitants of the South of Ireland [. . .] had assembled pêle-mêle on the Curragh to get a glimpse of the idol [...] But lo! the merry-go-wimbles, which had so unreasonably attacked the Royal stomach, (for even Kings are subject to these unkingly complaints), gave his Majesty full employment at the Phoenix Park.
1890–1904		Farmer & Henley Sl. and Its Analogues.