One thing about IPT is you will become very familiar with your baby's poop. This is good because it can give you a heads up about changes your baby is experiencing. You'll become well acquainted with how often your baby poops and the consistency thereof, which sounds gross, but it's a good thing to be up on. It can help you know if a certain food you've introduced causes a digestive reaction. You'll know immediately when your baby is starting to get constipated, or if diarrhea is coming on. It's a little harder to tell when they go in a diaper, because it gets all smashed.
An exclusively breastfed baby's poop is very liquid. The only solids are a few milk curds, which are tiny. Do not be alarmed, it's completely normal. It's not diarrhea. Diarrhea in babies is more linked to frequency of going than it is the consistency. As an aside, as we've experienced this, green poop with lots of gas could indicate your baby's getting too much foremilk. A simple Google search can help you find ways to correct this. What worked for me was feeding from one side at each feeding, but as I am not a doctor, you should do your own research and talk to your doctor about it.
One thing that can be concerning is foamy poop. I was really surprised when this happened with our first, and it happens a lot more with our second. Foamy poop needs no further description I guess, you'll know it when you see it. Just don't worry about it. It's caused by your baby swallowing air when she's eating. Try some Mylicon and see if that helps; our daughter's foamy poop goes away completely when we use it. Of course, this is only necessary if your baby seems uncomfortable. Most of the time, foamy poops won't bother your baby.
You might also find that your baby holds her poops during certain situations. For example, even though our girl is only three months old, she generally does not poop at night. She also doesn't poop when we're at other people's houses or out in town. It's amazing how early babies can control those muscles they use for pottying.