what if you feel like you need to have a bowel movement and all that expels is a clear or white mucus?
You should see your doctor immediately. Mucus in the stool is indicative of a range of disorders mentioned in this article – http://www.healthhype.com/what-causes-mucus-in-bowel-movement.html
But only mucus on its own can be a sign of serious bowel disorders. There are some other less serious causes like internal hemorrhoids but professional medical attention is necessary. Your doctor will need to examine you and conduct the relevant investigations before making a final diagnosis.