I Took Some Milk Of Magnsesia And Discovered It Was

I took some milk of magnsesia and discovered it was bad by the fishy taste. It didn't take long to work but the cramping was beyond belief! I actually cried the whole time. Now 2 days later I have not had a bowel movement and I usually go every day. I am concerned and worried because my urine was really really red today. Could it have done some damage to my stomach?