how long should I wait to see a doctor for black poop?
I have not taken Maalox for 2 days..
Ideally you should see a doctor immediately. It is difficult to say conclusively but depending on the frequency of bowel movements and so on, it should be out of your system by 2 to 3 days or longer if you are constipated. While some antacids do affect the color of the stool, it is important to exclude any gastrointestinal bleeding that may be occurring for other reasons.
You may find more information on this article :
at least 2 days