Green Stool for a few days (I didn't eat spinach)

Hi guys,

Since yesterday morning I've had green stools, but I haven't eaten anything greenish like asparagus or spinach that usually turn stools green. I though It would have been just a one time thing, but all of my stools yesterday were green. Again this morning it was green and looser (still formed, but when I flushed it got cloudy). Yesterday I was very gassy and today I've had some gut pain, but nothing bad, I've just been once to the bathroom today.

What may this be? any ideas? should I worry or something?

Oh, I should also say that I switched from Lialda to Pentasa 2 weeks ago. I initially thought that may be a cause, but the change was sudden and like a week and a half after I switched. Anyway, any help would be appreciated!

Do you take iron pills? Those can make your stools greenish or even dark brown, almost black looking.