No shortage of stupidity with that proposal. Why doesn't the organ recipient just go to CDC Headquarters and simply ask for a direct injection of the HIV virus, or go to Provincetown and leave his rectum exposed when he walks down Commercial Street. Allowing a virus load access to the thin walled, easily penetrable rectal epithelium is almost as sure a way of catching the disease as injecting it.
A long time ago in a nation far, far away we were making hospital rounds with the hospital's head of infectious diseases and we came across a lady who had had an anyphylactic reaction to some food she had ingested, carrots, shellfish etc. She said she was stunned when the emergency room personnel, along with injections of epinephrine through her skin. inserted a theophyllin suppository into her rectum.
"Who would have known that some medicine put there (in her rectum) would have worked here (in her lungs)?" was all she said as she pointed to her chest