>2x ultra-marathons >26 miles, or at least 5 marathons completed

Yes, and it seems like it's really a 7.5x risk increase. Still pretty spectacular, though!

I really wonder what could cause that. Randomly throwing out possible causes: 1) blood redirected away from gut, 2) overuse of NSAIDS, 3) ultraprocessed foods (gels etc), 4) strange microbiome issues (gels + stress in gut from extreme exertion = altered gut flora?)

The study that found the result is DOI: 10.1200/JCO.2025.43.16_suppl.3619