sulfasalazine

It can cause a sun sensitivity so be sure to wear sunscreen when you go out in the sun and after a while it may give your skin a slight yellowish tinge but that's normal. It can also cause headaches and nausea when you first start it.

A little research on sulfasalazine indicates that it can induce a folic acid deficiency. So taking some folic acid and perhaps also a multiple vitamin to balance out the nutrition may be a good idea.

This quote is from Life Extension magazine:
http://search.lef.org/cgi-src-bin/MsmGo.exe?grab_id=0&page_id=2224&query=ulcerative%20colitis%20folic&hiword=FOLIA%20ULCERATE%20ULCERATED%20ULCERATING%20ULCERATION%20ULCERATIONS%20colitis%20folic%20ulcerative

"Two case-control studies have shown that folate may protect against the development of colon cancer caused by ulcerative colitis. The most recent study showed that folate use for at least 6 months reduced the risk of colon cancer by 28 percent in 98 patients who had ulcerative colitis for at least 8 years. Of the patients with ulcerative colitis, 29.6 percent developed cancerous lesions. The greater the dose of supplemental folate consumed, the lower the rate of colon cancer. Scientists concluded that “daily folate supplementation may protect against the development of neoplasia in ulcerative colitis” (Lashner BA et al 1997). "

You need a folate supplement while taking it.