dribbling urine while having bowel movement

[cough cough]

This is becoming more severe and its uncontrollable.

[Padded53]

This kind of sounds like a form of Stress Incontinence but (I assume) you are either on the toilet or wearing a diaper when this happens so at least you are protected from an embarrassing leak one way or the other. That said whenever you see a significant change in your usual urinary habits it's best to consult your doctor.