Ok, I got Innova Evo...

[sissani]

... not the red meat one but the other one. With the poultry and stuffs.

I remember reading on here it can take months for him to actually get used to it? I dont want to have to try another food at the first sign of abnormal poops, if it will get better later on if I stick with it...

So how long should he be on it before I can determine whether or not this food is agreeing with him?

And what should I do if the diahhrea does show up again before that?

[gypsy_girl]

That is a great food, but NOT an alternate protein source. It may work though, depending on the allergy. One of the signs of overfeeding with this food is diarrhea ( as with alot of meat or high calorie food), so if you do get it, you will want to cut back some. Use the feeding guideline and adjust accordingly.You should know where you are after a couple of weeks or so.
If you do get loose stools, depending on how bad they are, and why you think the dog got them, you have a few options. Switching back to the HA until you have a good stool, and trying some other food. Using a pre and probiotic with a digestive enzyme and continuing with this food and see where you get, or cooking a very bland diet for a few days, then trying the food again (or a different kind)