I also found Movicol to be effective. The very first time I had chemo, I ended up with what the doctor called a 'plug' (in my bootom). I was truly in agony because I could feel it there but couldn't move it. Someone brought me an enema which didn't work at all and in the end I saw the GP. I don't know which was worse - the pain of the constipation or the doctor inspecting my bottom! Anyway, she said to go home and take two Movicol satchels immediately. If nothing happened then take another two about five hours later. Well, about two hours later I thought I might be able to go and boy, did I go! The whole lot came out with no pain or trouble. I've been a Movicol fan ever since. It's a softener and doesn't irritate the bowel and give you that feeling that some laxatives can. I think the key is prevention-start taking the Movicol the day of treatment (or even the day before) and don't wait until you are actually constipated. Good luck!