I Have Been Prescribed Polyethylene Glycol Due To Constipation After

I have been prescribed polyethylene glycol due to constipation after gall bladder surgery. at first it wasn't working,then a doctor suggested milk of magnesia. I started having bowel movements soon after. But after 4 days My bowel movements are mostly diarrhea-like. I have not taken polyethylene glycol for one day. I only used 2 doses of milk of magnesia and have not used for two days.
How long can I expect the diarrhea symptoms to last? Should I still be using polyethylene glycol?
My appetite has not fully returned, but i do eat solid food twice a day and drink plenty of fluids.
Today I had aparasentisis(?) done to remove blood from the operation because of a distended abdomen.
Friday I see my doctor to have a foley catheter removed and to find out when I can return to work.