Have any of you experience digestive issues after receiving a head injury? Do certain foods bother you and make you feel bad that used to never cause problems?

I've been talking to a women at the barn were we keep our horses and she been feeling really bad for a couple of months. All of her problems started after after she got her neck/head jarred pretty good while riding - though did not fall off. I'm thinking that maybe she has a whiplash type injury and is suffering from PCS. Many of her symptoms sound very familiar to Jacquie's and what I have read about here - constant fatigue, exercise making things worse, heightened anxiety, possible thyroid issues and others along with the digestive issues. None of the doctors can seem to figure out what's wrong.