What kind of hedge bush is it? There may be something deficient in their diet they are trying to supplement. I have found often that as I introduce other plant species into where my goats graze, some of what I thought were their favorites become untouched. It wasn't that that was their favorite plant... It was just their only option. I would be pretty concerned about the stool issue... thats not abnormal when there is a drastic change in diet, but lasting more than a couple of days could mean serious health risk. Check out this chart at the link below. I did not realize that azaleas were so toxic to goats. Most goats will readily eat them, unlike nightshades, which they seem to instinctively know are poisonous. The azalea bushes are all over my property... except where the goats graze. Fortunately I did a great deal of research on this subject before we got goats. I posted an ad on CL and gave away about 80 bushes to clear some of the land.
They did get out a couple times, and I'm pretty sure they ingested some of the azaleas. Symptoms were disorientation, bloat, head pressing... it was pretty scary. The second link is about azalea toxicity in goats. If this is what your feeding them, it can be fatal. The second link will be helpful for quick reference if you think this is what you are dealing with. Good Luck!
http://fiascofarm.com/goats/poisonousplants.htm
http://www.lsuagcenter.com/NR/rdonlyres/9D4CFAC1-C254-41D1-B81F-2D044B960D0C/69757/AzaleaToxicityinGoatsMay2011.pdf
