I haven't gone to the bathroom today...help?

I've had problems with constipation before...but lately, my bowel movements have been normal, and I've been going at least once a day, sometimes even three. Today, I made sure to eat a lot of fiber, drink 8 cups of water, and I ran my daily 2 miles. I haven't been able to go to the bathroom today, though...and I feel extremely bloated. So I used a Dulcolax Suppository, yet I still feel somewhat bloated. What could be a cause for this?