18 mos old and diarrhea?

I know we all have more than one kid so maybe you all can help. My 18 mos old has had diarrhea for two days. Not sure what's going on. She has her first molars, she is happy as can be with no symptoms of anything else... She had diarrhea 5xs yesterday and 4xs today. I backed off of fruit loops( thinking it could be a culprit). She eats and drinks like a champ still. I just haven't a clue as to what's going on.  She is supposed to have her shots Tuesday. Any thoughts? Do you think I shld cancel her appt? Feeding her applesauce, yogurt, no juice. She has had milk and has everyday so I don't see milk being the culprit. She loves oranges but I haven't let have them for 3 days. I'm just confused??? Help!