When using this product a temporary, but harmless, darkening of the stool and/or tongue may occur. Reye's syndrome: children and teenagers who have or are recovering from chicken pox or flu-like symptoms should not use this product. When using this product, if changes in behavior with nausea and vomiting occur, consult a doctor because these symptoms could be an early sign of reye's syndrome, a rare but serious illness. Allergy alert: contains salicylate. Do not take if you are allergic to salicylates (including aspirin), taking other salicylate products. Do not use if you have - an ulcer, a bleeding problem, bloody or black stool. Ask a doctor before use if you have - fever, mucus in the stool. Stop use and ask a doctor if - symptoms get worse, ringing in the ears or loss of hearing occurs, diarrhea lasts more than 2 days. Ask a doctor or pharmacist before use if you are taking any drug for - anticoagulation (thinning the blood), diabetes, gout, arthritis. If pregnant or breast-feeding, ask a health professional before use. Keep out of reach of children. In case of overdose, get medical help or contact a poison control center right away (1-800-222-1222).