I had been having some pretty severe digestive issues for a while, and it got to the point I was miserable - it was literally affecting my quality of life.
Before I decided to seek out a gastro doc, I wanted to try and resolve it myself by eliminating potential causes from my diet. So one by one, I started experimenting with dropping different things.
In the end, it didn't turn out to be my protein powder, but in the process (and not wanting to give up my PWO smoothie, which I enjoy thoroughly), I came up with this powderless version that I'm very happy with. Try this if you just want to give the powder a rest for a while, or are seeking out a more 'natural' approach:
1 cup liquid egg whites
1/8th cup unsweetened almond milk
1/2 cup oats (raw)
2-3 packets splenda or stevia (I use both together)
2 tbsp good quality cocoa or cacao powder
3 tbsp powdered peanut butter (e.g. PB2, Jif, etc.) OR if your macros allow, 1-2 tbsp natty PB
1 cup 1% milkfat low salt cottage cheese
1 frozen banana, cut into chunks
Blend and enjoy!!!
Edit: You can also add 1-2tbsp instant ground coffee for more of a 'mocha' flavor and caffeine kick.