An apparatus for accessing a bodily passageway, comprising: an endoscope (1606, 1607, 1608) comprising: - an insertion portion configured to extend into the bodily passageway; - a flexible drive shaft which extends through the insertion portion transferring rotary motion generated by a power supply; and - a drive collar (1615, 1616, 1617, 1618, 1619) comprising: -- a stator (1683, 1706, 1802, 1902) disposed at an intermediate portion of the insertion portion, comprising a slot; -- a rotor (1680, 1700, 1800, 1900); -- a gear (1703, 1803) disposed within the slot, being configured to receive the rotary motion from the flexible drive shaft and transfer the rotary motion via the slot to the rotor; and -- a watertight seal (1681, 1701, 1801) disposed between the stator and the rotor and protecting the gear (1703, 1803) against water exposure through the slot; and - a drive tube including a lumen configured to receive the insertion portion, wherein a helically-wound thread is disposed on an outer wall of the drive tube; wherein the rotor (1680, 1700, 1800, 1900), which is coupled with the drive tube, is rotatable over the stator (1683, 1706, 1802, 1902), wherein the rotary motion of the gear (1703, 1803) causes the rotor (1680, 1700, 1800, 1900) to rotate via the rotary gear portion on the inner surface of the rotor (1680, 1700, 1800, 1900), and the rotary motion is transferred to the drive tube via the rotor (1680, 1700, 1800, 1900); and characterized in that the drive tube is detachably associated with the drive collar (1615, 1616, 1617, 1618, 1619). - an insertion portion configured to extend into the bodily passageway; - a flexible drive shaft which extends through the insertion portion transferring rotary motion generated by a power supply; and - a drive collar (1615, 1616, 1617, 1618, 1619) comprising: -- a stator (1683, 1706, 1802, 1902) disposed at an intermediate portion of the insertion portion, comprising a slot; -- a rotor (1680, 1700, 1800, 1900); -- a gear (1703, 1803) disposed within the slot, being configured to receive the rotary motion from the flexible drive shaft and transfer the rotary motion via the slot to the rotor; and -- a watertight seal (1681, 1701, 1801) disposed between the stator and the rotor and protecting the gear (1703, 1803) against water exposure through the slot; and -- a stator (1683, 1706, 1802, 1902) disposed at an intermediate portion of the insertion portion, comprising a slot; -- a rotor (1680, 1700, 1800, 1900); -- a gear (1703, 1803) disposed within the slot, being configured to receive the rotary motion from the flexible drive shaft and transfer the rotary motion via the slot to the rotor; and -- a watertight seal (1681, 1701, 1801) disposed between the stator and the rotor and protecting the gear (1703, 1803) against water exposure through the slot; and - a drive tube including a lumen configured to receive the insertion portion, wherein a helically-wound thread is disposed on an outer wall of the drive tube; wherein the rotor (1680, 1700, 1800, 1900), which is coupled with the drive tube, is rotatable over the stator (1683, 1706, 1802, 1902), wherein the rotary motion of the gear (1703, 1803) causes the rotor (1680, 1700, 1800, 1900) to rotate via the rotary gear portion on the inner surface of the rotor (1680, 1700, 1800, 1900), and the rotary motion is transferred to the drive tube via the rotor (1680, 1700, 1800, 1900); and characterized in that the drive tube is detachably associated with the drive collar (1615, 1616, 1617, 1618, 1619).