Do you void and/or evacuate by the clock? Have you used anything to make yourself more regular? Does anyone else really give a sh*t?
Yeah, I'm really anal about being regular. Hahaha...sorry that was a really bad pun, but it's true. I get in a bad mood if I'm not.
if you're not regular, you really need to go back and look at your diet. your body really needs you to be regular, as we realize how rampant colon cancer, obesity, etc. is in our society... not to preach...just look at what you're eating and make sure you're eating enough fiber. you can find fiber in whole grains (rather than white ones), beans, and green veggies. if you already eat your fiber, you can up your poopage by eating very concentrated fiber (figs, prunes) or, if you just happen to be constipated, check out any number of 'smooth move' teas on the market - however, these are for specific constipation, not regular use.
or and something simple that is often forgotten: have plenty of water. Stool needs water in order to pass out easily. This is especially the case if your diet is full of fiber, and you still have problems being regular. Fiber needs a lot of water to pass. There is even a special name for of constipation that derives from fiber, when there's too little water around. So your minimum of water should be 2 liters, the more the better, especially when it's hot. Water seriouly mobilizes your metabolism rate in many ways.
I'm a regular kind of guy. I eat enough fiber and whole grains and good stuff so it isn't really a problem for me at all. If I get into a situation where I'm not regular I just drink a lot of water like Kastenfrosch said and that'll usually do it.