I discourage anyone to do fasting the way most people typically do it, meaning fasting no food or water during the day, sleeping a lot and go into extreme food ingestion at night and go to bed with a full stomach. during Ramadan people traditionally cook heavy fat meals, fill and stretch the stomach at night and do less physical activity/mouvements. I know of some people who sleep all day and wait for night to wake up and eat. the whole body goes into extremes. This way of doing is very unhealthy I believe.
I believe in the benefits of intermittent fasting and research has shown possible benefits, but there is a way to properly do it and this does not involve big food ingestion at night, sleepping with full stomach ,nor to cut water. Not drinking water especially when the day is hot in the summer is scary to me.
Serious Medical conditions can be automatically excluded of Ramadan fasting, and crohns is a definately a serious condition, even in remission. By imposing such a stress on the whole body, I believe we risk trigger a flare or causing other unwanted issues. I really discourage it.