I'm 49 and I thought fit and healthy.  For the last three week my poo has been black.  No change in how I go and my bowel habits have remained the same.  I have no stomach pain, bloating, fresh blood, mucas or anything  and the poo looks completely normal in size.  I stopped taking vitamin D three weeks ago, do take HRT but apart from that I can't think why this would be this way.  Do I need to be worried.  I have sent off for a FIT test.  Thanks in advace for any replies to my post