Since Oct 2015 I suddenly stopped having complete evacuation of stool.After few there was burning sensation in my stomach at around 4 am in the morning.After doctor's medication I felt well.Then I became habitual to my incomplete stomach clearance.But since past few days my stool's texture and color is wierd.sometimes green like cow dung and sometimes very dark brown.Something wrong which I can feel.Further I feel lazy all day Inspite of having enough sleep.