From: Zardoz ®

Defecation (expulsion of feces through the anus) occurs with varying frequency, ranging from 3 times daily to once every three days or more. When defecation occurs more than 3 times per day and has a liquid consistency it is referred to as diarrhea. When defecation occurs less than two or three times a week and consists of a hard, dry stool that is difficult to pass, it is referred to as constipation.

Diarrhea. Loose, frequent stools occur with everyone periodically, but if they persist it can indicate other problems.

Constipation: Eating a diet containing ample whole grains, fruits and vegetables and drinking plenty of fluids is the best way to protect against constipation.


http://www.madsci.org/posts/archives/jun2001/991699020.Gb.r.htm