Secretory diarrhea is characterized by painless, large volume, watery diarrhea (usually > 1 L), minimal effect on fasting, and a stool osmolality gap of less than 40. There are numerous causes of secretory diarrhea, including secretagogues, laxatives, medications, endogenous detergents, and bacterial enterotoxins. There are no controlled data on the efficacy of any specific therapy. Conservative measures, including fluid and electrolyte replacement, should be provided for all patients, and antidiarrheal therapy is indicated in more severe cases. No specific pharmacological therapy has proved effective in most cases, and antidiarrheal therapy is relatively nonspecific.