Fiber. No, seriously. Things like this are usually due to a lack of fiber in the diet, so what you'll want to do is take supplements. On top of supplements, try prune juice (gross, but it helps), leafy greens, broccoli, corn, cereal, anything that says it's high in fiber. Eat a lot of these, not just a little. Also, you'll want to remove certain things from your diet, like bananas.
Furthermore, drink a ton of water. Sometimes, it's also the fact that you haven't had enough water that binds you up. Don't just drink juice or sodas.
If all else fails, sometimes, coffee helps for me. It's the caffeine jolt.
As for laxatives, I tend to think of them as a last resort, not because of the part that мilкii Ƹ̵̡Ӝ̵̨̄Ʒ pointed out but instead because some of them will also warn you that you may become dependent on them if you end up using them before trying to solve your problem with everything else.
