An endoscope is provided, being insertable in the colon of a patient, in a self-propelled manner, by driving a plurality of endless belts mounted along the outside surface of a flexible section of an insertion tube thereof, and having a cleaning mechanism therein to be easily cleaned after use. A self-propelled colonoscope (1) is an endoscope insertable in the colon by driving endless belts (10) mounted along the almost entire length of a flexible section (4) of an insertion tube (5), and having guide pipes, which guide returning endless belts, being mounted in the insertion tube thereof, each of said guide pipes being provided with an opening for a cleaning brush (35) and a casing (31), which surrounds the endless belt driving unit, being formed with a cleaning window (33), said window being provided with a lid (37).

An endoscope is provided, being insertable in the colon of a patient, in a self-propelled manner, by driving a plurality of endless belts mounted along the outside surface of a flexible section of an insertion tube thereof, and having a cleaning mechanism therein to be easily cleaned after use. A self-propelled colonoscope (1) is an endoscope insertable in the colon by driving endless belts (10) mounted along the almost entire length of a flexible section (4) of an insertion tube (5), and having guide pipes, which guide returning endless belts, being mounted in the insertion tube thereof, each of said guide pipes being provided with an opening for a cleaning brush (35) and a casing (31), which surrounds the endless belt driving unit, being formed with a cleaning window (33), said window being provided with a lid (37).

A self-propelled colonoscope comprises control part and an insertion tube including a distal part, a bending part, and a flexible part. The distal part is equipped with an image pickup element. Two or more endless belts each of which is circular in cross section extend along the surface of the flexible part from a guide hole positioned at a distance of less than 3 cm from the distal end of the flexible part to the control part. The endless belts are driven by a driving mechanism located at the control part. They are guided from the inner surface of the flexible part to the outer surface through the guide hole. The endless belts are held by guide hooks which are arranged on the outer surface of the flexible part. The length of each endless belt is equal to about 105% to 150% of an imaginary endless belt fully tensioned and extending from said control part to a respective guide hole. The colonoscope can be easily, safely and rapidly inserted into the colon without causing pain to a patient.

The self-propelled colonoscope (1) is self-inserted into a colon by driving endless belts (17) mounted on the outside of the bending section (15) of the insertion tube (9). The cross section of the endless belt (17) is substantially circular and a rack gear teeth having a circular cross section are formed on the outside of the endless belts (17). A recess having a circular cross section and pinion gear teeth which correspond to the shape of the endless belt and the rack gear teeth. Since the endless belt (17) has a circular cross section, it can easily bend in all radial directions. Upon insertion of the insertion tube (9) into the colon, the endless belt (17) can easily follow the movement of the insertion tube (9).

A self-propelled colonoscope comprises control part and an insertion tube including a distal part, a bending part, and a flexible part. The distal part is equipped with an image pickup element. Endless belts extend along the surfaces of the flexible part from a guide hole positioned at a distance of 3 to 10 cm from the distal end of the flexible part to the control part. The endless belts are driven by a driving mechanism situated in the control part. They are guided from the inner surface of the flexible part to the outer surface through the guide hole. The endless belts are held by guide hooks which are arranged on the outer surface of the flexible part. The colonoscope can be safely and rapidly inserted into the colon without causing pain to a patient thanks to the particular length of the endless belts. The endless belts are driven to guide the colonoscope by the effect of friction between the endless belts and the wall of the colon. The colonoscope does not cause abdominal pain nor accidents such as bleeding or perforation of the colon even in cases of adhesion of the colon from previous abdominal surgery, because it can be smoothly inserted without changing position and shape of the colon. When the endless belts slacken, their tension can be corrected with an adjustment mechanism connected to the colonoscope.