MoviPrep
"Had a colonoscopy yesterday and the consultant was very impressed by how well this had worked on me!

I found it tolerable to take. The first few mouthfuls are a struggle and I could not work out if it was because of the lemon smell or the taste so I tried drinking the next glass holding my nose - IMO it is definitely the salty taste that makes it hard to get down. Best advice is to drink it as fast as possible so it doesn't register so much on your tastebuds. Once it is down the lemon smell after-note is not so bad!  
Things really start to move quickly and dry toilet paper stings after a while. Use some sort of cream to alleviate it. It dehydrates too so drink water because a catheter vein (anaesthetic) is harder to find when dehydrated!"