Sir, on 4th of February, 2017 I got open heart surgery, thereforeafter, my stomach was disturbed. I took Entamizole, Novidot and Bismol for my stomach. The stomach is still up set but my tongue color is showing some black spots. However, I am using the heart medcines, like lowplat, concor, sofvasc-5 mg Rovista, and Volta 150. will you be kind enough to let me know why my tongue is showing black spots.