Agree with the above.
Bubblebath is a big culprit especially some brands are very harsh.
I used as a bumcream or any redness when still on nappies a mixture of vaseline, zink ointment and fungicide like canalba, canesten etc. No colourants and fragrance as this irritates skin. When they get older I leave the canesten tube in the bathroom cupboard to use when necessary when a itch start.
This get beter when they learn not to wipe from the back. Also stay away from coloured and printed toilet rolls and some brands of toiletpaper is just not good.
Me: 42 low AMH
DH: 50 all well
2012
IUI #1 BFN
Nov 2012 IUI #2BFP! M/C 7 weeks
2013
IUI #3, #4, #5, #6
IVF #1 Sept 2013 BFP! 4 weeks So Blessed! Oct 2013 10 weeks no heartbeat. Evac. Heartbroken
2014
IVF #2 IUI #7 IVF#3 IUI #8 BFN
IUI #9 Sept 2014 BFP!!!!! 4 weeks. Thank you God, you have answered our prayers
28 May 2015 Little Boy born.