Abstract: An apparatus for anastomosing a digestive tract including a plurality of substantially U-shaped retainers that are disposed around an annular groove in the outer periphery of a support tube formed of a soluble material. The annular groove has inner side and bottom surfaces and the retainers are disposed in the tube at a plurality of locations along both the inner side surfaces and the inner bottom surface of the groove in a radial array. The retainers have spaced apart ends and are each made of a shape memory alloy or resin endowed with a property of moving the spaced apart ends to a closed state at a predetermined temperature, or made using a spring member, or provided at the spaced apart ends with magnets that will attract each other. In use, the retainers are released from the support tube when the soluble material of the support tube is dissolved and assume closed state when they reach the predetermined temperatures to clamp the digestive tract therebetween.