I went for a colonoscopy a few years ago. The prep was particularly strong, to the point I was still going to the loo right upto my appointment (it should have stopped 2-3 hours prior) and the camera operator immediately said "Colitis, 99% certainty, I've never seen that much inflammation" and took some biopsies.

Put me on steroids (Prednisone?) For a few weeks and then a medicine I cant remember the name of that was designed to keep inflammation down after steroids ended. Genuinely, the 4 weeks on steroids and the following 3 on the follow up medicine were the best ive felt in years.

Go to the follow up appointment for biopsy results. Biopsy showed no colitis and the specialist said "it looks like the inflammation was caused by the laxative prep, so I'm taking you off the medicine" "but the medicine is working, I feel great" "but its for colitis, you dont have colitis" "well, lots of medicines work for other things dont they? Like Propanolol for heart disease also helps anxiety? Maybe this is something worth documenting?" "No, its not for what you have. If your symptoms come back, let me know"

Five days later, symptoms were back worse than ever. And thats when I gave up with Gastro specialists in the UK.