I suggest trying senna tea. You can get senna tea pods at natural grocers for less than $2.00. You let them sit in just-boiled water, just like you would tea, and drink a glass or two when you are backed up. It works really well, it's cheap, it's natural. The only thing is you have to drink a lot of water when you are taking senna. There are also senna pills but I don't find them as effective as the tea. Also... there is a brand of tea called "Smooth Move" (I think?) if you don't want to buy the pods and do it yourself.