HI Jane, I'm sorry to hear that your are having diarrhea with the actenol. Have you discussed this problem with your dr.? if you haven't he should be informed that your are reacting this way. Four days is a long time to go without nutrients being absorbed by the body. This link will provide a list of side effects. You'll notice that diarrhea is a problem for 10% of the people taking it. Hope your feeling better soon..take care..phyllis
http://osteoporosis.emedtv.com/actonel/actonel-side-effects.html