Anyone been prescribed these meds or have self medicated this way ?

hey everyone .. I’ve been dealing with UC since I was 13 and I’m now 35. Until 6 months ago I weighed 102-108 lbs my entire life and could never gain weight and avoid eating to keep symptoms at bay, a chef who eats 1 meal a day isn’t normal, from ages 21-34 I was on 0 meds with very little symptoms probably cause of the starvation … during Covid I flared up like I never had before, was extremely fed up of the pain, diarrhea, and hunger feeling, I did some research and came across a certain medication that on the Canadian govt website said is used to treat chronic diarrhea. The medicstion was an opiate. So I took it upon myself to test out self medicating. I made sure NOT TO ABUSE and use truly like medicine.
I took an 20mg OxyNEO in the am and 20mg in the pm, after 4 months of medicating. I gained FIFTY pounds, and 0 symptoms and was CRUSHING 3-5 massive meals a day, 1-2 bowel movements a day that were solid and the length of my arm. I was extremely surprised by these results.. has anyone else here been prescribed opiates ? What results have you had ? And how do I bring this up to my family doctor / GI that this is how I gained all my weight and how I have 0 symptoms..

( yes I do know opiates are addictive but i truly feel like if you treat it like medicine instead of something to get high, which I know may sound weird but I never “felt high “ I needed to smoke my kush to get the “ high “ feeling)