so how did your guinea pig manage without hay for a few days? and what did you use to replace the hay? This (broken link removed) states that hay should be the primary source of their diet because its good for their digestive systems. Did you just feed them fruits and veggies and did that lead to a somewhat wetter-than-usual stool? Sorry for all the questions, I just wanted to know if anything changed with your guinea pig just in case i happen to run out of hay for a few days myself.