what kind of diet do you have the baby on. My friend had constant issues with her yorkie until she switched to raw diet and hasn't had an issue since. I have heard of Yucca but perhaps finding an holistic vet and getting further info on it would be wise.
slippery elm is great for the runs and constipation and that came straight from my vets mouth.
perhaps a diet switch and adding a probiotic to create a healthy flora in the intestinal tract.
Hope this helps a wee bit
here are a couple of links to check out.
Pet Remedies on Earth Clinic Pet Nutrition and Animal Wellness - Mercola.com Common Canine Health Problems | Dog Illnesses