I had a remarkable 20+ years of hardly a blip on the horizon with my pouch.
Developed some newer things as of the past few years.
Seems to be things that fall under an "IBD" type heading, but GI won't call it "Crohn's" yet. But I've written here before, he's said that he's seeing "old pouches" come back with "new symptoms" of the IBD type.
A + Calprotectin does indicate bowel inflammation. Someone with irritable bowel disease (and I'd assume irritable pouch disease) would not show a + Calprotectin. Only an inflammatory disorder of the bowel will.
My GI didn't want to send one on me (why? never really could figure that out for sure). Daughter's GIs at Children's LOVE LOVE LOVE this test (I suppose because it's so non-invasive and with kids, that's always a plus). Her first flare showed a Calprotectin of >2,000. Her last (she's on Humira and MTX) showed something like 55. Yay! She'll have another one this Monday, we visit with them next week for a check up.
I'm sure a scope will help them visualize and see if there's obvious inflammation, and they can also send biopsies. My pouch itself looks "pretty ok" most of the time, but there is low-level inflammation (I think most pouches read as this), and he's suspect of my perianal and cuff area, which seems to be my worst offender these days. I did have a + C-reactive protein, and a mildly elevated Sed Rate, too.