Hello, I have concerns regarding dark green colored, almost black stool I have to go poop 2-3 sometimes 4 times in few hours of waking up but I dont need to go rest of the day usually I do feel itchyness in Anus/rectum area, sometimes burning sensation. I don t have any difficulty passing bowel, I am not constipated and usually not thick in texture. I wonder what causes it? Should i be concerned?