hello there I'm not sure if anyone has suggested this, I too have struggled with this all my life irritable bowel and a severely blocked bowel to the point of having to ingest this horrible stuff from the chemist called agarol my god hit me like a ton of bricks, coming out of both ends that day just awful, however when I had to have chemo for breast cancer I was told pear juice by one of the nurses.....yes it works a treat, also try to incorporate prunes in your diet and if you don't like pears you could try prune juice, try not to get to reliant on artificial help....drink heaps of water, yes ive been slack lately but I can consume large amounts of water and that really helps. fibre has to be in the form of fruit and veg, but research what is high fibre and be careful with fruit just because its fruit doesn't mean a lot of it is good for you and especially with the fruit sugars. and I think too you have to find foods you enjoy eating and will stick to and that will help you. Also, if you can move a little more do some form of exercise. I think someone also mentioned the same, more liquid and movement and fibre... You don't want to go passing out that's not good....Do you know why you pass out or feel light headed etc, that is because the main artery from your brain runs down the same side of your body that when you strain it gets restricted by the pressure on it and the next minute your on the ground similar to when someone puts someone into a sleep hold position around the neck, I cant think of the technical names or even the area of the body or veins at the moment really bad chemo brain tonight, I live with an RN and she was telling me this the other week!!!