If you do not have a daily bowel movement, it does not mean you are constipated. Having more than one movement a day does not mean that you have diarrhea. Constipation is hard, dry stool that are difficult to pass, and diarrhea is watery stool more than three times a day.
Most healthy adults experience diarrhea or constipation at some point, but a consistent change in your normal bowel habits (such as color, frequency, or consistency) should be discussed with your physician. This is especially important if you are over the age of 50 years.
National Digestive Diseases Information Clearinghouse. "Facts and Fallacies About Digestive Diseases." National Institutes of Health Publication No. 04–2673 Oct 2003. 18 Jan 2011.
American Academy of Family Physicians. "Constipation." FamilyDoctor.org Jul 2007. 18 Jan 2011.