SWIM say No, Weed is actually good for the gut. SWIM has never heard of weed causing a Flare-UP. And has not ever had one smoking weed.
But weed smoke can cause flareups too right
But weed smoke can cause flareups too right
I would very much doubt it. Weed is actually a very good thing for those with IBD to take as it helps with the pain, nausea and increases your appetite. Many doctors will unofficially recommend it to their patients.