What side effects may I notice from receiving Asacol HD?

Side effects that you should report to your doctor or health care professional as soon as possible:

-allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
-blood in the urine
-bloody diarrhea
-breathing problems
-chest pain
-pain in the lower back or side
-pain when urinating
-rash, fever, swollen lymph nodes
-signs and symptoms of infection like fever; chills; cough; sore throat; pain or trouble passing urine
-signs and symptoms of liver injury like dark yellow or brown urine; general ill feeling or flu-like symptoms; light-colored stools; loss of appetite; nausea; right upper belly pain; unusually weak or tired; yellowing of the eyes or skin
-trouble passing urine or change in the amount of urine
-unusual bleeding or bruising
-unusual or severe stomach upset or pain
-unusually weak or tired
Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):

-gas
-headache
-mild hair loss
-nausea, vomiting
-stomach pain

This list may not describe all possible side effects for Asacol HD. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.