>>119453
If you fucked up your gut with antibiotics or other shit. Than it's hard for you to digest stuff and your body shoots it out.
Or you eat something like 1-2kg of broccoli at once, because you saw what bodybuilders eat spread over the day.
Or you normally don't eat a lot of fiber and therefore you have to add fiber rich nutrients slowly to your diet.
creatine diarrhea can come from not using hot water for creatine and the undissolved crystals attach to your stomach wall.
protein comes from not having sufficient stomach acid in the stomach, or the protein is too lean(add carb), or intolerance.