I often have stomach aches and excessive buildup of gas in the abdomen. I have been experiencing a painful excretion for quite a sometime. I happens on  its own especially the first excretion, afterwards, the pain persists but is less painful. My stool color also changes. Often the color ranges from yellow and would change to dark brown. Today morning the first excretion was yellow color and the second one after 2hours was dark brown Sometimes the excreta is long & solid and sometimes its loose or semi-solid.