Treatment tool for endoscope

1. A treatment tool for an endoscope comprising:

an insertion section which is capable of being inserted from an opening for insertion of the treatment tool, the opening being provided at a proximal-end portion of a channel of the endoscope to an inside of the channel, the opening having a mouth ring which communicates with the channel and a plug which is fitted together with the mouth ring, and the insertion section being capable of being inserted from the mouth ring to the inside of the channel via the plug;

an operation section provided at a proximal end of the insertion section;

a connecting member provided at a distal end of the operation section, the connecting member being capable of attaching to the plug depending on an insertion of the insertion section to the inside of the channel;

a guide member that has a tubular shape, that is externally fitted around the insertion section at the proximal end of the insertion section that is connected to the connecting member, and that is rigid; and

a fixing section provided at a distal portion of the guide member, the fixing section being located in the mouth ring when the connecting member is attached to the plug, the fixing section being capable of fixing the guide member to the mouth ring by fitting to an inner wall of the mouth ring due to an expansion of the fixing section toward an outside of the fixing section, wherein;

the insertion section and the operation section are capable of being fixed to the endoscope by an attaching of the connecting member to the plug and a fixing of the fixing section to the mouth ring,

the fixing section includes:

a fixing member having an elastic body that is expandable toward an outside thereof;

a pressing member which is capable of pressing the fixing member in an axial direction of the fixing member; and

a locking section which is placed at a distal portion of the guide member, and

the fixing member is sandwiched between the pressing member and the locking section to thereby elastically contract in the axial direction of the fixing member, and the fixing member is capable of fixing the mouth ring by pressing an inner surface of the mouth ring by expanding toward the outside thereof in the mouth ring in accordance with the pressing by pressing member.

2. The treatment tool for an endoscope according to claim 1 , wherein

the insertion section includes:

a sheath that has flexibility;

a needle tube with a tubular shape that is inserted inside the sheath and having a distal-end portion that is sharpened; and

a stylet that is passed through the needle tube, and wherein the operation section has a slider that is capable of moving the needle tube and the stylet back and forth in an axial direction of the sheath relative to the sheath.

3. The treatment tool for an endoscope according to claim 1 , wherein

the fixing member consists of an elastic body that is externally fitted around the guide member.