Asacol (generic: mesalamine) is a prescription medication used to treat ulcerative colitis. Asacol belongs to a group of drugs called anti-inflammatory agents. These work by stopping the body from making a certain substance that may cause pain or inflammation.

This medication comes in delayed release tablet form and is usually taken 3 times a day, with or without food. Do not chew, divide or break Asacol tablets. Swallow Asacol tablets whole.

Common side effects of Asacol include headache, nausea, and upset stomach.