Can patients with kidney failure use glycerin suppositories?

Yes: Glycerin is not absorbed through the rectum, which is why it draws water out of the body into the stools and helps one have a more productive bowel movement. It is probably safe to use, but if you use it for more than a few days in a row, you run the risk of dehydrating yourself, which is bad in kidney failure. I would suggest you see your doctor if the constipation is not improving.

Glycerin use: I have thought about your question and have dome a little reading. I can find no reason that a glycerin suppository should harm someone who has kidney failure except for acute kidney failure due to massive fluid loss. Any added fluid loss under these circumstances will only make matters worse.