I agree with everything that's been said here.
However, I would add to check your temps. If your hot and cool side are dialed in, no worries.
If your hot side or cool side is too hot or too cold, then your BP will not properly thermoregulate and may have trouble digesting and pooping.
I assume it's what everyone else said; small and young prey items equals less poop, they don't poop all the time anyway, especially when growing, etc.
What are your temps on the hot and cool side? Humidity would be helpful as well.