Can drinking red bull be a cause for bloody stool? I have been drinking at least 1-2 red bulls a day for the past 2-3 weeks due to working 3rd shift and trying to stay alert. I have recently for the past several days had blood in my stool where it turns the water a slight pinkish red. Other than that, I am feeling fine, no pains, no fatigue , I am 25 years old, male, active and in healthy condition. Does this have anything to do with it or could it possibly be something else?