Black Lab with soft stool

Question
I have a 10 month old male black lab. Approximately 3 weeks ago he woke up one morning and vomited in his crate. I took him outside and he had diarrhea. I got him to the vet that morning and was told he caught a virus. I took some of the diarrhea with me to the vet and the vet said stool showed no signs of worms. He was prescribed a medication and a bland diet for a week. I gave my dog the medication and followed the vet's instructions for the bland diet. His stool seemed to harden on the bland diet so I transitioned my dog back to his dry food. Within a few days a soft stool appeared, it was not watery like before, it had the consistency of pancake batter. I called the vet's office again and the vet told me my dog must not have gotten over what he had before and prescribed another round of prescription medication. The medication did nothing for this stool it is still the consistency of pancake batter. My dog's behavior has not changed thru any of this. He eats and plays like he always has. Is it possible he may have a food allergy or intolerance to his dog food that is causing the soft stool?

Answer
Keep working with the vet.  Perhaps try the bland diet again.  Don't be too quick to switch dog chows.  Most dogs will thrive on most chows, and allergies and intolerance to a chow is not nearly as common as those selling expensive chows say.  

Much of what I read on the net about dog chow isn't consistent with what I see in the guide and service dog programs I have been a part of for a long me.  I see thousands of active, healthy dogs thriving on mid grade chows including Pro Plan and Iams.  The schools very seldom have to switch to the more expensive chows.  Of course, health is a major factor in selecting their breeding stock.

I recently discovered this site is infested with an organokook that is adding claptrap to my answers.  She may be selling BARF in a box.  One of the most objective sites on dog chow is http://www.woodhavenlabs.com/