@karina1954 I have stage 4 CKD since 2016. I’ve had a colonoscopy since that time. If you’ve never had one before I’ve got to say that the prep is worse than the procedure itself. If anything the prep is good for your kidneys because you will be avoiding red meat, having soft foods, then clear liquids (avoiding red or purple fluids) and consuming SO much clear liquids as part of the pre-med. it not only cleans out your GI system; it thoroughly flushes your kidneys in the process. My hopes and prayers are with you that it all goes well!