Distal end hood for endoscope and endoscope system

An endoscope system, comprising:

• an endoscope;
• and
• a distal end hood for the endoscope,
• the endoscope including:
• a distal end portion;
• a bending portion;
• a flexible portion which are disposed in sequential order from a distal end side;
• an insertion part configured to be inserted into a subject being tested;
• a gas feed conduit which is disposed inside the insertion part, the gas feed conduit configured to supply a feed gas;
• a distal end surface of the insertion part on which an opening is formed, the opening configured to be communicated with the gas feed conduit and to spray the feed gas;
• and
• an observation window which is provided on the distal end surface, the observation window configured to make observations within the body of the subject being tested,
• the distal end hood for the endoscope being formed in a circular cylindrical shape, the distal end hood configured to be mounted on the distal end portion of the insertion part of the endoscope and circularly surround a front side of the distal end portion of the insertion part of the endoscope,
• the distal end hood including a conduit including a first conduit which is disposed inside the distal end hood, and a second conduit which is communicated with the first conduit and is disposed outside the distal end hood, the conduit being formed of a flexible tube,
• the conduit further including:
• a first end portion on which a first opening is formed, the first opening being fitted together by insertion with the opening of the distal end surface of the distal end portion of the insertion part and being connectable to the opening, when the distal end hood is mounted on the distal end portion of the insertion part, the opening configured to spray the feed gas;
• and
• a second end portion on which a second opening is formed, the second opening being disposed at a position away from the distal end surface toward a proximal end side of the insertion part, when the distal end hood is mounted on the distal end portion of the insertion part,
• wherein the second opening of the conduit is positioned at the flexible portion when the distal end hood is mounted on the distal end portion of the insertion part.