Surgical devices and methods are provided for preventing the formation of post-operative adhesions. In one device, an envelope of bioabsorbable material defines at least one opening, and a layer of bioabsorbable adhesion-preventing material is disposed on an exterior surface of the envelope. A rigid or semi-rigid barrier member is at least partially disposed in a space inside the envelope, without adhering to the envelope such that the barrier member can be pulled out of the envelope through the opening. In another device, a rigid or semi-rigid barrier member is removably attached to a layer of bioabsorbable adhesion-preventing material by a controlled adhesive. In another device, a rigid or semi-rigid bioabsorbable barrier member, such as compressed cellulose, is attached to a layer of bioabsorbable adhesion-preventing material. The envelope of bioabsorbable material may include cellulose or oxidized regenerated cellulose. The adhesion-preventing material may include chemically modified sodium hyaluronate and carboxymethylcellulose.