Yep, unfortunately even on a low carb you usually have bloating and water retention somewhat with endo. My re said that you can hold as much as 8 to 10 pounds of water weight with it, especially if the endo is affecting your bowels too. I usually weigh 1 1/2 to 2 lbs lighter after I have been up for an hour. A good indication to tell if you are holding excess water is by looking at your eyelids when you wake up. Mine are always puffy when I first wake up.

Unfortunately I dont know of anything to help with it. BCP can slow down endo and the side effects may be lessened however you can still have bloating from that too.