Because these tests don't have a great reputation and are expensive and "out of interest" for you means potential for another "crisis".
You don't want or need another crisis. Why not just try eating as healthily as possible and respect your guts? Make time to eat wisely? Why bombard your guts with crap and then wonder why they rebel? You're not anaemic so no reason to think that you have a malabsorption issue. You just need help to eat sensibly.