The Collaborative International Dictionary of English v.0.48:

ca-ca \ca-ca\ n.
   n. [see cack.] Feces; excrement; -- used in talking with
      very young children. [baby talk]
      [PJC]

The Collaborative International Dictionary of English v.0.48:

ca-ca \ca-ca\ v. [see cack.]
   to have a bowel movement. [baby talk]

   Syn: defecate, shit, take a shit, take a crap, crap, make.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

ca-ca
    v 1: have a bowel movement; "The dog had made in the flower
         beds" [syn: stool, defecate, shit, take a shit,
         take a crap, ca-ca, crap, make]