IBS and Anal sex

TMI (sorry🙈) basically I’ve been with my other half just over a year and last night we tried anal for the first time.. I felt a bit un-comfortable but my OH was great! He told me to hold onto his hand and he will go as softly and gently as he can.. we didn’t use lube, he used his saliva instead.. I just want to be able to feel more comfortable doing it but I also have ibs and Crohn’s disease and have read that it can help depending on the situation.. can anyone give me advice on how to feel more comfortable and maybe how anal actually helps🙈 thank you xx