A device for treating a diverticulum includes a containment device and a bushing. The containment device includes an elongate conduit. The bushing is in the conduit of the containment device. The bushing includes a heat-shrink material. The bushing has a first tubular shape including a first open end and a second open end. At least a portion of the diverticulum in an inverted state is positionable into the first open end. The bushing is configured to transform from the first tubular shape toward a second shape upon heating the heat-shrink material. The second shape includes at least a portion of the bushing radially inward relative to the first tubular shape. The bushing in the second shape is configured to hold the diverticulum in a radially compressed inverted state.