I missed years of periods due to not weighing enough. Didn't miss them exactly, but when they did reappear, omg, hormones and crohns omfg!!!!!
Just about through menopause and I can't say I miss them, but the crohns is also still diabolical. I just hope I am through the menopause and not cos i'm skinny, now that would be a nasty shock lol.
I sincerely think females with bad crohns do expect periods to be fewer and far between, or missing for quite some months/years. Depends what they weigh I think.