Scott says he's not convinced that the problem is the erythritol and that I didn't just happen to get sick. I do have a diagnosis of IBS, but this was pretty completely unlike how that normally manifests (and it doesn't happen very often at all). When I have IBS trouble, it usually passes after about an hour and then is gone for weeks or even months. This lasted pretty much all day with a bit of trouble the next day, too.

When something like this happens, I'm more inclined to look and see if there are any changes in my diet or environment rather than to assume I'm sick.

But I have agreed to test it next week.