Abstract: Endoscopic apparatus, including a probe (9) having an anterior component (12) and a posterior component (14), and a flexible dual-sleeved tube (31). The flexible dual-sleeved tube consists of a flexible external sleeve (26) and a flexible internal sleeve (36) within the external sleeve. The sleeves are coupled between the anterior component and the posterior component so as to define an enclosure (37) between the sleeves, which enclosure is inflated in order to propel the anterior component within a lumen (49).