Thank you! I’m curious if anyone has experienced severe flare up & then gone into full remission
When you say remission do you mean on symptoms or on inflammation? Because I have achieved remission on symptoms many times but have always had inflammation in the pouch, either low grade which has been called "simmering", or something more than simmering. One can live with simmering inflammation in the pouch if the symptoms are controlled, and I have done so for almost 30 years. That's not ideal obviously, but my quality of life is quite good.
As for Mexico, I was there in 2000, 8 years after getting my pouch. At the time, I took some chances that were not advisable as far as eating local restaurant food at various destinations on the way to Chichen Itza in the Yucatan Peninsula, and had zero issues during and after the trip, despite some arguably unsafe eating behaviors. There is a tendency on this board to look for cause and effect in health issues, and sometimes they just are not knowable. My father recently had a serious flare of his IBS, and he blamed it on my dry rub chicken, although he had eaten that same dry rub chicken half a dozen times previously with no IBS flare. I would suggest to you it's better to focus on treating the issue you have properly - something may or may not have triggered the issue while you were in Mexico (could have even been the air travel), but the task now is to get better.
BTW I took rotating antibiotics continuously (not on and off) for 25 years plus, and am now on Remicade for 5.5 years and doing well, but I do not have an inflammation free pouch. Just a few scattered ulcers and most of the inflammation is at the J Pouch inlet. Because of the lack of backsplash valve I think many J Pouchers eventually get some level of inflammation in that area, due to basic physics and the mechanics of the Pouch, and there is nothing that can be done to change physics or the mechanics of the pouch, as far as backsplash stool goes.