Embodiments of the invention include a medical device for accessing a patient's body portion and used for diagnosis and treatment of medical conditions. Embodiments of the invention may include a particular endoscopic positioning mechanism for placing an endoscope and an additional treatment device within desired body portions in order to assist in diagnosis and treatment of anatomical diseases and disorders. In particular, a medical device according to an embodiment of the invention may include an outer flexible tube and a positioning mechanism configured for rotating one portion of the flexible tube relative to another portion of the flexible tube.