I have the same thing sometimes...upper left, lower left....lower abdomen...lol....think I hurt in every inch of my belly so far.It is indeed gas sometimes...I used to be very worried about it too and really paranoid but look....you should know that cancer causes D only if it is located in the right side (ascending) of the colon. The left side cancer causes constipation. And Kathleen is right...cancer doesn't give so many symptoms...by far!