Rectal pain, pain while inserting the bottle tip, gas, and joint/leg pain may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Rarely, this medication may make symptoms of your condition worse rather than better (acute intolerance syndrome or sensitivity reaction). Tell your doctor right away if you experience any of these unlikely but serious side effects: worsening stomach pain/cramping, worsening bloody diarrhea, severe/prolonged headache.Tell your doctor right away if you have any serious side effects, including: chest pain, shortness of breath, severe stomach/abdominal pain (especially if spreading to the back), yellowing eyes/skin, dark urine, signs of kidney problems (such as change in the amount of urine, blood in the urine).A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: fever, swollen lymph nodes, rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.