Stop to use the restroom

I have IBS (irritable bowl syndrome) and sometimes the bowel movement urge comes on strong and out of no where .. i really cant help it and meds cause all sorts of other side effects. A few times I have had to stop, mid drive, to use the bathroom. I explained to the Rider and they seem ok but a few days later I notice a 1-star rating pop up.
I mean, if I have to go, I have to go.
Why can’t people understand that?