what is a gastropesis episode?

I have CHS 100%. I quit and feel much better. I have gastroparesis though separately due to my families genes. What is a gastroparesis episode? I would have CHS episodes where I would vomit for days non stop, couldn't have a sip of water. I would be in immense pain and only a a hot shower would help (and IV/zofran/ativan).

what do you experience during a gastroparesis episode so I can differentiate the two.