ask your doctor if virtual colonoscopy can be done instead of direct invasive colonoscopy as both have equally good diagnostic value. nowadays virtual colonoscopy is widely done and drastic preparations are usually not needed
I am a pro at his I have had 5 done in 20 yrs, different drs like different preps. Mine all made me do liquids 1 day prior then start at 5 pm with dulcolax tabs then fleets phopho soda then repeat fleets phospho soda, the last one I had depleated me, I went into hypovolemic shock. Not all that uncommon with the prep I followed. Your Dr prefers a less aggressive method, follow his advice this works for him or he would have changed his prep formula by now, Good luck it should be painless, enjoy the sedation you will feel, you'll be out and awake in what seems like 5 seconds. You'll be a little dreamy and should be starving and ready to eat everything asap when you get out of there. Unless your 2nd irrigation is completely clear by the end I would recommend the third irrigation though.