Document Type


Patent Number

US Patent 5,919,136

Patent agency

United States Patent and Trademark Office

Publication Date



BioEnterics Corporation (Carpinteria, CA) ; University of Iowa Research Foundation (Iowa City, IA, US)

Application Number


Date Filed


Total Pages

5 pages


A device for evaluating anorectal function. The device is a silicone gel-filled deformable artificial stool adapted for transanal insertion within the rectum and having an adjustable volume, and a shape consistency and size similar to a normal stool. The device has an elongate extensible silicone elastomer outer shell overlying and affixed to a coaxially mounted inflatable inner shell to create a sealed cylindrical space between the outer and inner shells. The elastic outer shell preferably incorporates a radiopaque material homogeneously dispersed within the silicon elastomer, alternatively, inner balloon affixed thereto. Radiopaque fluid is introduced into the cylindrical space to provide a means for radiographically observing the in situ deformation of the device when placed within the rectum of a subject. One end of a flexible fill tube projects within the volume enclosed and defined by the inflatable inner shell and is affixed thereto. The opposing free end of the fill tube (tail) extends away from the inner tube. A lumen within the fill tube provides leak-proof fluid communication between the interior of the inner shell and the free end of the fill tube. The free end of the fill tube includes a self-sealing valve inserted within and plugging the lumen providing a means through which a fluid or air may be injected into, or withdrawn from, the inner shell to adjust the volume of the device in situ. The free end of the fill tube may also be used for withdrawing the device from the rectum. The device has a shape and consistency of a stool and further includes means for adjusting the volume of the device in vivo to evoke an optimal sensation of stooling.