Brie, a year or so ago there was a long thread here that featured the dark and STAINING urine caused by Asacol and Pentasa. Many have noticed what you have. Some have also endured tests to determine the cause of their "kidney" problems. Many have had to replace their toilet seats due to the splattering of urine causing stains on the seats. While I jave never been on either product, I do recall this thread talking about
it. I will try to locate it for you.
Update: Here's the thread: http://www.healingwell.com/community/default.aspx?f=38&m=601324
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CD, Ankylosing Spondylitis, lupus, small fiber peripheral neuropathy, avascular necrosis, peripheral artery disease, degenerative disc disease, and a host of other medical problems.