First of all: Yes, you definately get the bad stories here, because people in remission don't seek out a forum to use for venting, support, advice, wisdom. So here's on to another story which is not 100% positive. Sorry..
I hope it is still relevant as knowledge...
I was on biologics from 2000-2016 (except a pause of less than a year), so 15 years+...
I was diagnosed in '99 and in 2000 I was offered Remicade as part of a study. I had a good effect from it, and continued until my doc proposed I tried Humira in 2005. Humira kept me pretty much in remission until suddently in 2011/2012 my kidney function started going down due to inflammation in the kidney tissue (Interstitial Nephritis with granulomas).
My GI suggested I could try to stop the biologics because of the chance it was a drug induced reaction, so I did.
After less than a year in an almost permanent flare and on steroids, I had to start again, going back to Remicade. I was on that until 2016 when I started getting really sick and further loosing kidney function. I am down to about 40% now.
That was when I quit for good, hoping I can avoid dialysis or a kidney transplant. So far it has been stable, but I am trying to prepare mentally for the worst.
The docs have different theories on what happened/happens to me: could be a manifestation of CD, could be the biologics.. I researched this quite alot, and I lean towards the explanation being the biologics suppress my immune system so much that infections are allowed to attack the kidney tissue.
It is generally reported that doctors treating with biologics should be aware of the risk their patients develop something with "-itis".
It is difficult for me to say "don't do biologics" because I owe it to biologics that I could finish my education and start a family. But had I known then what I know I would have said no thanks and started right away on what keeps the CD pretty much under control now: Methotrexate, diet, supplements, trying to reduce stress, proper sleep, and exercise.