You can use fleet mineral oil disposable enema, with chronic kidney disease. It does not have water or salts. After pushing the enema in, do not retain it for more than 5 minutes and immediately sit on the toilet seat. This should help in passing the motion.
Please feel free for your follow up questions.
This is the reason I mentioned, that it should not be retained in the rectum. If it is not absorbed, it would not cause any problem. That way it will be far less oil than what we consume in our food. You cannot take the water and salt based enema at all and the only option left is suppository.
It is pleasure and privilege assisting you.