My poppy was diagnosed with Giardia. She given medication for 30 days. During which time, I noticed she started having diaherra. Once she completed the medication I had her retested. The results were negative, however she continued to have diaherra. The Vet recommended I give her boilded chicken breast and rice for 2 days. During the 2 days her stool was hard. But, when I tried to reintroduce her food. She started having diaherra again.
Could it be the food. However, she was fine before the medication. Or was it the medication.
Medications and antibiotics strip the system of good and bad bacteria. Not replenishing can lead to continued digestive upset/diarrhea, etc. I suggest you purchase a good probiotic to give to replenish the good bacteria. They can be found at most pet stores or feed supplies. You can also use plain yogurt, although a specific probiotic would have a broader bacteria spectrum and might be better in your situation.
You can also give Kefir, a highly cultured product you get at a natural food store. My puppies love it and all have nice little tootsie roll poopies. It has about 10 different strains of friendly bacteria.