ummmm, if it is plastic plants not sure he would crap it or even that he could, but my cats after they eat something they are not supposed to will throw it up after a couple of days. Good luck.
It's usually normal to have bloated stomach after the meal...but will subside usually after some time.. this is my one after 10 mussels are you 100 % there was no food left in the tank for him to fines they will eat any old rotting food? Have a look at this http://www.vetsci.org/2004/pdf/275.pdf
this happens a lot they eat stones hope it helps good luck