A method for removing a stone from a patient comprising the steps of: providing a suction evacuation assembly which includes a sheath and one or more side arms; inserting and positioning a distal end of the sheath into a lumen or cavity of a patient's body containing a stones; connecting a tube to one of the side arms and to a collection bottle; connecting another tube to the collection bottle and a negative pressure system; visualizing the stone or foreign body using a scope inserted through the assembly; activating the negative pressure system in order to remove the stone from the cavity if the diameter of the stone is narrower than an inside diameter of the sheath and the side arm, or performing a lithotripsy on the stone to create fragments with a decreased diameter which allow the passage through the assembly; and collecting the stone in the collection bottle.