OPTION 1 involves 6 one-hour visits to the Massachusetts General Hospital (MGH) Andrology Clinic over a 9 month period. At each visit you would be asked to fill out questionnaires and to provide a urine, semen, and blood sample. Following Visit 2, you are asked to switch your brand of mesalamine medication. After 4 months, you change back to your original brand of medication. The change in medication will be done in consultation with your primary GI doctor. If the cost of co-payment is greater for the new brand of medication, we will provide compensation to cover the difference. In the case you do not have prescription drug health insurance coverage, the study will reimburse up to $4000 to cover the cost for Asacol, Pentasa or Lialda medication taken during your study participation.