It's hard to say. IBS/IBD is often associated with AS. There's also a form of Spondy called Enteropathic Arthritis that is characterised by GI tract problems.

Have you tried going without the spicy foods for a few weeks to see what happens? Give it 6 to 8 weeks to give your gut a chance to heal, and then slowly reintroduce various components of your favourite foods. There might be a specific ingredient you're reacting to; it might be the spices, say. See how you feel.

You should probably get an appointment with a GI specialist and see about having a gastroscopy (both stomach and colon). Really, that's the only way you'll know if there's anything untoward going on that is causing this.

I hope it eases soon. I'd be lost without my spicy foods.

Hugs,

Kat

A life lived in fear is a life half lived.
"Strictly Ballroom"