A system for performing minimally invasive procedures in a body lumen of a patient including a flexible catheter having a first lumen and a second lumen, the first and second lumens terminating in a distal opening at a distalmost end of the catheter. First and second flexible guides are separate components from the catheter and removably insertable into the flexible catheter and movable axially through the lumen of the flexible catheter. The guides have a channel extending therethrough configured and dimensioned to receive an endoscopic tool for axial movement therein. The flexible guides have a longitudinal axis and a tube distal portion movable to a pre-shaped curved position with respect to the longitudinal axis when exposed from the flexible catheter.