Is there any artificial sweeteners in the granola bars?  Some of them can be migraine triggers.  As can chocolate, aged cheeses, nitrates, MSG, as mentioned above.  On this list, I see nuts and seeds as migraine triggers. 

https://client.myoptumhealth.com/myoptumhealth/guest/page.esync?view=prelogin.learn.learnLanding&command=article&articleCategory=10+Foods+That+May+Trigger+Migraines&path=Pain+Management---Common+Aches+%2B+Pains---Headaches+%2B+Migraines&article=7c639dcada579110VgnVCM1000005220720a____

Thanks for the replies.    DS has told her not to eat any more of the granola bars or peanutty stuff for a while - then she'll have a bite of two of one and see if she gets a migraine. 

MSG - which triggers my migraines can be found in granola bars.  Maybe that's your culprit.  If you do a Google search you'll find some of the other names for MSG.  For me, I discovered this years ago and I can not remember which granola bar I stopped eating.  It took me a long time to guess that one!

So, maybe?

Could be something else in the bars which is acting as a migraine trigger, too.

I'd tend to think probably the migraines aren't allergy related, but I suppose it's possible.

The stomach is probably related to the headache, though.   

My granddaughter just turned 13. She's been getting migraines for the past year or two (as does her dad) but she's had a rash of them for the last week or two. My son noticed that they started when they bought a large box of peanut granola bars at Costco - and she's been eating them daily. Suspicious that there might be a link, he told her not to eat any for a while - and the migraines stopped. Today he OK'd her having another and within half an hour she said her stomach felt 'weird'.

All three kids had eczema, one of the kids has asthma and my son also has eczema plus their mom's father is walnut allergic/asthmatic.  And me - peanuts/asthma.  So we know they're the classic atopic family. 

DS has told her not to eat any more peanuts for now. I'm suspicious that the migraines are hormonal but I know there's also a link to food intolerance...and the weird stomach makes me nervous. 

What are your thoughts on this?