Ulcerative colitis affects approximately 500,000 people within the U.S. For mild to moderate disease, 5-ASA is considered the fi rst line medication to achieve both induction of remission and maintenance of remission. Since the use of sulfasalazine over 40 years ago, numerous new formulations have been created to minimize side effects and maximize drug delivery to the affected colon. Here, we have detailed the currently available 5-ASA formulations and explain why there is room for new and improved 5-ASA formulations. In addition, we will summarize the latest trials detailing the use of MMX mesalamine and where it may fi t into the treatment algorithm for our patients with mild to moderate ulcerative colitis.