I'm always constapated and have recently been given off more gas than usual?

Lots of foods claim to be colon detoxers, read up on colon detoxing, but most say drinking water more so you may or may not find thats of any help, and in answer to your constipation and gas - that usually happens due to a sudden change in diet, ie: healthy to unhealthy or vice versa :)

Some good answers given already like plenty of fruit and fibre plus water, but you could try Dulcoease. It's a tablet that helps soften your stools so they come out more easily. You can also take this with a laxative. The gas could be because you has food alergy, maybe to wheat or gluten, these are quite common and can cause constipation and gas, also headaches and tiredness (sometimes skin irritation) I hope some of this has helped you.