I have acid reflux issue since 9 months and it subsides greatly if i manage lifestyle and take punarnavarisht. I took it for past three days and also ate watermelon last day...today a portion of my poop was greyish black in colour (not tarry or sticky). I have no other problem than reflux which comes and goes depending on eating and lifestyle. Does this blackish poop a cause of concern or it could be due to diet. Dont remember eating anything coloring except some black olives/punaranava risht and a red water melon. I consumed jaggery too if it could have affevted.