I don't know what you have available in the UK, but here in the States you can get fiber pills or powder. Check in your stores to see if one is less expensive than the other. I started with a soluble/insoluble blend, and couldn't take the pain. So I switched to an entirely soluble brand, which caused some pain, but I felt I had no choice at that point. The pain lasted for about a week of 3x daily use, then I adjusted to it. It has helped very much with the D. I would try it if I were you, even if you had to cut something out of your budget elsewhere.