| abstract |
An insertion unit of an endoscope in accordance with the present invention comprises, from the distal end thereof, a distal section, a bending section that is freely bendable, and a soft section having flexibility. The soft section comprises a small-diameter portion formed on the distal side thereof, a large-diameter portion, and a tapered portion linking the small-diameter portion and large-diameter portion. At least part of the tapered portion is disposed forward an endoscope portion separated 70 cm from the distal endoscope end. Assume that the insertion unit is inserted into the large intestine and the distal section is introduced the shortest distance into the appendix. In this case, the distance from an endoscope portion located at the anus to the distal end of the distal section is known to generally range from approximately 60 cm to approximately 70 cm. Therefore, when at least part of the tapered portion is disposed forward the endoscope portion separated 70 cm from .the distal endoscope end, the great ease of insertion is guaranteed. |