To give a little background, I've never been very regular... sometimes it could be 2 or 3 days between bowel movements. However, I've recently been eating more fruit and less junk food, in an effort to lose weight, so I'm getting more regular now and feeling much better for it. In fact, two days running I've passed what could accurately be described as mini torpedoes, and afterwards I feel SO much better! 
I can now understand why some people have colonic irrigation, though I've never been brave foolhardy enough to try it.