For the past 2 months I have had heartburn that wakes me up at night. It causes vomiting and has been lasting up to 8 or more hours. There is no rhyme or reason to it since it also comes in during the day. This morning I noticed that my stool is black. I've taken otc meds, Tums, rolaids, pepcid, even tried a remedy my mom suggested (teaspoon of baking soda and water). Nothing is helping!