Yup......usually bars of soap with moisturizers, oils or perfumes can cause trouble with barriers and tapes sticking to skin, unfortunately........
I've been an ostomate for nearly 37 years now and there are only a few soaps I personally use, but Ivory being the main one, I almost entirely use just Ivory around the stoma.
(Ivory is also best for people who have sensitive skin allergies)
I belong to a local Ostomy Support Group and many of our members state that they have chosen to use no soap in that area where the pouch will be applied, unless they absolutely have to, they just gently use a soft washcloth repeatedly with warm water then blot dry. Personally, I still prefer soap.
....however ..... I also do in fact use Baby Shampoo as an entire Body Wash, and sometimes around the stoma, just because it's so gentle.....and there is also a brand name of Baby Shampoo called "Parents Choice" sold by Walmart in the Infant aisle that is great, hypoallergenic and free of many unwanted things.
.......though I still support the Ivory bar as best..........
Also, a few other notes to toss out here..... on occasion I use some Natural Homemade Soaps made by some of our local Amish Communities, no oils and such, .... you might be able to find certain 'plain soaps' among those Homemade in a local Organic Store if you have one .......and during the occasional times when my skin becomes irritated and sore for various reasons, one soap that you wouldn't think would be a good idea at all but soothes me is Natural made Beeswax Soap....it's a very hard bar soap and actually seems to help protect my skin from all the wear 'n tear of ripping off pouches........after cleansing the skin area very well, if I have a sore area, I first use a snip of actual Aloe Vera plant leaf to squeeze the healing plant juice directly on the sore area and allow it to completely dry.........then do NOT wash that off.........that sticky, slightly slimy Aloe Vera juice straight from the plant is not only quite healing, but it sort of forms a slight 'seal' like Liquid Bandaid, and it doesn't prevent any barrier or tape from sticking at all ......it's amazing.......
Of course, everyone's skin is different and different tips will work for different people, but it's worth a try if ever needed xoxo
Just throwing some extra ideas out there for you to try.
~Doe