Did these issues start when you changed food? I'm asking this because the gagging, bile and occasional poop issues are all things my boys did while on Natural Balance Limited Ingredient Brown Rice and Lamb which I considered a high quality food and thought they were doing well on it for almost 2 years~except for what I considered an occasional gagging, bile and poop issues. It happened about once a week and was very random and there was slight blood in a poop on a few occasions. I did not ignore the blood and I went to the vet, had blood work and nothing was ever found wrong. I had always chalked it up to it eating too fast or empty tummy when other issues were ruled out with vet checks. Doodlebug was at the vet in late summer as a matter of fact and his blood work was "perfect" for a sick dog.
I have always purchased the large bag of NB and divide it into small Ziploc bags and stored it. When I went to feed them late one evening I realized there wasn't the one last bag I thought. They were starving and out of desperation I went to Target thinking I would buy a can of something to feed them for the night and run out in the morning to Petco to pick up their "good" food. Instead I picked a bag of kibble~ OMG ~they have not gagged, thrown up or had a bad poop since. GASP~it's PURINA ONE Beyond
Healthy Pet Food Products: Purina ONE® Beyond?
The reason that I am repeating this entire story is that your little one sounds to me just like what I was going through. I firmly believe after 8 weeks of not picking up nasty poop, no gagging, no bile and not one threw up that it was the NB at the root of our problem. In short, I believe that you should schedule a vet visit to address your concern but at the same time I would consider the food choice a possible cause. I've come to realize with my own experience that "premium" foods might not be all they are cracked up to be. Who would have thought PURINA ONE BEYOND would solve all our problem.