I am 18 1/2 and have been experiencing weird digestive problems from 2 months. Firstly I started to have a feeling that I aint able to clear my stomach, second it continued and my stool colour changed from brown to dark brown, now from one month I am farting alot and sometimes it causes discomfort, I had black patches (not exactly black -can say dark brown) in stool from 1 month, and today I got shocked when I saw full black tarry stool -- guys please help -- I aint having fatigue, nor weakness nor anything like that, only those digestive problems!