Do I have Internal Damage from synthetic marijuana? The Doctors believe I m fine, because I didn t tell them about the K2? I am having an issue and I don t know what to attribute it to. I am having very violent jerking movements in the lower left side of my stomach. I am bleeding through my backside, I have a headache, and feel like I m going to pass out. The doctors did a full EKG, Lithium level check, kidneys/liver check etc... and said I m fine as far as they can tell; I was referred to a neurologist