Asacol is a medication primarily used to treat inflammatory bowel diseases, such as ulcerative colitis and Crohn's disease. It contains the active ingredient mesalamine, which helps reduce inflammation in the intestines, alleviating symptoms like abdominal pain and diarrhea. Asacol is typically taken orally in tablet form and is designed to release the medication directly in the intestines. Patients usually follow a prescribed dosage regimen, and it is important to take the medication consistently for optimal results. Side effects may include headache, nausea, or abdominal discomfort, but serious reactions are rare.