Hi!!!
I was close to checking out the  supermarket/pharmacy options- but ended up in Sun Ray Health food shop instead-  she put me on to Dandelion Tea- which seems to have worked a treat....  Its quite mild though- so I guess it depends what level of help you need to 'get things moving' iykwim lol 

   I drink about 3 cups a day- really nice with milk and honey... seems to replace my coffee cravings.
Prob not much help sorry.