Experience with a new silicone prosthesis in the modified Thiersch operation for rectal procidentia in 16 extremely poor-risk patients is presented. The technique of implantation, structural details of the prosthesis, and the clinical results are described. The use of a new silicone prosthesis in the modified Thiersch procedure is a viable alternative in this group of patients. Surgical technique is a primary determining factor in preventing complications.