Thank you very much for the response. It does ease my mind somewhat!
Yes, they are safe. Most of us with cirrhosis commonly have an endoscopy and colonoscopy every year or so to screen and monitor the status of our varices. I have taken miralax many times with no adverse effects.
What can more problematic is any anesthesia type drug(s) you may be given. I assume this procedure is being performed by your gastro and she/he is aware of your cirrhosis?
If an anesthesiologist is involved (more common with endoscopy or total colonoscopy-up to the small intestine) I also always remind the anesthesiologist that I have cirrhosis when they come around just before any procedure. Just to be sure they are aware of my cirrhosis.
Twilight anesthesia, more commonly known as "conscious sedation" using (Versed and Fentanyl) is probably the safest anesthesia beside just a sedative to relax you. Versed causes partial or complete loss of memory. Fentanyl is a powerful synthetic opiate analgesic similar to but more potent than morphine used to relax you.
Surgery and general anesthesia are dangerous for patients with advanced cirrhosis so no elective surgeries should be performed using general anesthesia unless absolutely needed. I asked my hepatologist "Does this mean no nose jobs and tummy tucks?" She said "Yes", laughing. It can cause further liver damage, decompensation of cirrhosis or death in some cases. This is why your hepatologist needs to be informed of all medical procedures you have performed even if not related to liver disease.
I hope this helps.
Hector