Digestive tract device

A digestive tract device positionable in a digestive track of a living body comprising:

• a tubular portion configured to be positioned in the digestive tract of the living body, the tubular portion possessing a distal tip and a through hole opening at the distal tip of the tubular body;
• a retention unit positioned on a distal portion of the tubular portion, the retention unit comprising one of:
• i) an outwardly expandable member that is outwardly expandable to an expanded state larger than a portion of the digestive tract when the distal portion of the tubular body is located in the digestive tract to hold the tubular body in the digestive tract;
• and ii) an expanded member larger than the portion of the digestive tract when the distal portion of the tubular body is located in the digestive tract to hold the tubular body in the digestive tract;
• the tubular body including a folded portion at which the tubular body is folded in a folded condition of the tubular body, and the folded portion of the tubular body being held in the folded condition;
• and
• the folded condition of the tubular body being releasable when the tubular body in the folded condition is positioned in the digestive tract to increase a length of the tubular body.

A method comprising:

• introducing a tip end portion of a tubular body into a digestive tract in a living body, the tubular portion possessing a through hole, the tubular body including a folded portion at which the tubular body is folded;
• the tubular body with the folded portion being moved in the digestive tract to a predetermined position in the digestive tract;
• and
• increasing a length of the tubular body located at the predetermined position in the digestive tract by unfolding the folded portion.