Well, one of my turtles were having this problem where it was basically pooping out its intestines, then they'd go back in eventually. we couldn't figure out what was causing the problem, until we put it in a tank by itself and noticed after a day that there was a ton of gravel in the bottom of the tank and we didn't put it there... Turns out they have been eating the gravel in their tank. I took out all the gravel and put him back in the big tank and watched as the other one pooped out about 15 pieces of gravel. OOPS! So word of advise for any turtle owners, don't put gravel in their tank.