Hello, I am 24 years old male. I had tb. But i completed my medication in june. My all reports were good. But for some days not continuously but 2 or 3 days after after i saw my stool is blackish. Not overall but the sides of the stools were blackish. Also today morning i saw my stools sides were blakish.And at the end a small amount of stools were fully blackish I am taking acilog rd for 4 days. Yesterday my stool was fully good. But before  3-4 days it was slightly black. I am not sure that is it pure black or deep green or deep brown. But it looked like blakish. I have no pain in stomach. But i felt a mild pain for some seconds at the both sides  of my belly button. But that is so mild. And occurs after so many time. But i have mild nausea after taking food. Yesterday i ate rice, pulse, fish curry, eggs, some fast food including maggi and so much onion. And two cups of very dark coffee. Is it for the dark coffee?? Or is it some serious problem?? Help me please.