Hello, Thank you for using healthcare magic. First, you have to rule out, if have consumed this week foods that might give a black color to your stool such as beets, diets rich in green vegetables, licorice etc. Second, you have to rule out if you have taken these time medications that might color your stool such as oral iron therapy, Pepto-Bismol, etc. If none of the above mentioned causes is not possible than you should go under further investigation such as Fibrogastroscopy, abdominal ultrasound and full blood count, in way to rule out hemorrhage as a possible cause of dark stool. You should be for sure guided by a gastroenterologist. Hope this may be helpful for you. Please feel free to contact me if you need further explanations. Dr. Juarda