Green’s Dictionary of Slang

caca v.

[caca n. (1)]

to defecate.

[UK] ‘Gone to Ca-Ca’ in Pearl 5 Nov. 30: Mama and de Captain / Are gone to Ca-Ca.
[US] in Current Sl. IV:3–4 (1970).
[UK]R. Milward Man-Eating Typewriter 71: Don’t bite, no drool. Caca outdoors from now on.