You can feed your glider something that has laxative like properties, such as prunes, apples, or citrus fruits like oranges. If they don't eat the fruits then next time you mix your own HPW (or whatever liquid staple you use), you can mix in 1 tablespoon of chia seeds into it. Since chia seed is a natural mild laxative, it won't cause your glider to have the runs, but it will cause their stool to be looser... that is, if they actually EAT the seeds instead of spitting them back out like mine do...