I can eat Galaxy chocolate. No problem, and it doesn't trigger my IBS. The other day I ate a Galaxy Ripple bar instead of the ordinary block chocolate. I thought nothing of it, just thought it would be the same as the block chocolate.
But it affected my bowel movements the next day, and there was some slight discomfort low down in my tummy that day too.
The next day I didn't eat it of course. Instead I tried ordinary Galaxy block chocolate. No symptoms the following day.
I was on it quickly, and checked the ingredients. They were more or less the same except for one thing: Polyglycerol polyricinoleate, aka E476, aka PGPR. That is an ingredient in the Galaxy Ripple bar.
Cadbury's chocolate also contains it (that explains why I can't eat Cadbury's either. I never knew why. I think it also explains why Cadbury's flavour went right downhill a little while ago, and it's not nice to eat any more.)
E476 is an emulsifier; a cheaper version of cocoa butter. It does a similar job -to keep chocolate smooth.
Soya lecithin can also be used. (I am fine with that!)
Using Polyglycerol polyricinoleate maximises profits (of course.) as it's a cheaper ingredient. It is sourced from the Castor Bean (sounds natural...right?) Except that I remember when I was a kid in the 1950s, Castor oil ...very nasty stuff indeed -was used to "nuke" the guts in event of constipation! So not friendly for IBS-D!!
Just my story, but I thought worthy of mention for anyone who thinks chocolate triggers their IBS. I now have to carefully read labels, and chocolate without that ingredient is friendly for me and not a trigger food at all.