Is it normal for puppies to have on and off stomach sensitivity?

I’ve been raising my puppy for a little while now, and overall things are going well, but one thing I keep noticing is how sensitive his stomach seems to be.

Some days everything is completely fine, then out of nowhere I’ll notice loose stool or mild discomfort, even though I haven’t made any major changes to his food. I’ve been sticking to a consistent diet, limiting treats, and trying not to switch things up too often, so it’s a bit confusing.

I know puppies are still developing and their systems are adjusting, but I’m wondering how common this actually is. Is this just part of the process, or is it something I should be paying closer attention to early on?

For those who’ve already gone through the puppy stage, did your dog eventually grow out of it, or did you have to actively do something to stabilize their digestion?