Hi Charlie,
I'm CYY and I was diagnosed last December, after more than a decade of IBD symptoms (constipation from 2005-2007, diarrhoea from 2007-2016, bloating and abdominal pains from 2015 onwards).
After diagnosis, I went through 9 weeks of EEN. Technically, I should only be on EEN for 6 weeks, but my doctors chose to extend the period because I was still experiencing abdominal pains and they wanted more time to let my gut heal. I took 36 scoops of Modulen (1500 calories) every day and was able to gain 1.9kg by the end of 9 weeks. I know it may not sound like a lot, but I was severely underweight before EEN and now I'm only underweight. I did not manage to grow in height at all, however.
EEN has also solidified my watery stools (maybe a little too much). I used to have 4-5 BMs in a day (up to 7 if I'm in a flare), but now I only go once every 2-3 days. The downside is that I'm back to having constipation now, but the good thing is that all my BMs are now fully formed.
After EEN, I started on a immunosuppressant called Azathioprine, while reintroducing some foods like potatoes and chicken breast meat, and doing part-time EN. I was still able to gain a couple of hundred grams of weight every week everything was good so far.
Unfortunately, I was unlucky and fell into the 3% of population whereby oral Azathioprine caused me to develop pancreatitis, and so had to stop taking it immediately. I lost whatever weight that I had gained through EEN during my week-long hospitalisation. At the same time, I ruled 6-Mercaptopurine (6-MP) out from my list of available medications as well, which my doctors described as being the "evil cousin of Azathioprine", sharing some 70% of its chemical composition. However, I need to be quick to point out that most people respond well to Azathioprine and 6-MP, and that the benefits of immunosuppressants far outweigh the side effects (however scary these side effects may sound).
Thus, I was given the choice between Methotrexate (MTX), Humira and Remicade. I ended up going for the bottom-up approach and choosing the weekly subcutaneous injections of MTX, a type of immunosuppressant which I had just started 3 weeks ago. The reason I chose it was because 1) I can develop antibodies to the other two biologics and that means that those are one-time options, 2) biologics such as Remicade and Humira are really strong stuff, so they should only be used when I desperately need it, and 3) they are very costly. MTX, on the other hand, does not cause the formation of antibodies, so it can be used, in theory, for an indefinite period of time. So far, the side effects of MTX for me have been nausea and fatigue, but I've been able to gain back some weight since my hospitalisation.
All in all, I'd suggest trying out EEN if you're looking to gain some weight. They're nutritious (albeit awkward tasting) specially formulated milk that have almost no side effects. I admit that it does require tons of perseverance to stick to this regime religiously, but it's just as good as taking the steroids. And the good news is, if you're in a flare and all else fails, you can always come back to it. I'm sure that there're many people here who have their own success stories to share about EEN too.
If you're considering what type of maintenance medication to go for, I'd suggest trying out immunosuppressants before moving on to the stronger biologics. Azathioprine and MTX are good choices to begin with. Crohn's is an unpredictable disease, and complications can occur anytime. I think it would be better if you can save your big guns for those times of emergency.
Ultimately, the decision is yours to make, but I hope this guides you in your decision somewhat.
I wish you all the best in your Crohn's journey.
Cheers,
CYY