Pay a visit to http://medicamentation.com/ingredient/misoprostol/!
"Misoprostol decreases the amount of acid that comes in contact with it. Cytotec exerts a protective effect on the gastrointestinal mucosa by increasing mucus and bicarbonate ion secretion and by increasing mucosal blood flow. Cytotec exerts a protective effect on blood flow and the lining of the stomach wall."