Sometimes I have a histamine reaction and it can give me the "throwing up" feeling. In fact, it HAS caused me to throw up a few times! Once it was from a very ripe banana. I ate about half of it, felt funny and threw up about 3 to 5 minutes later. It's not a real "allergy" but more of an intolerance thing. I can handle bananas just fine - just not super ripe ones.

I first got sick from histamine by accidentally eating a lot of high histamine foods at once (in a single day). I had hot cocoa (cocoa is high in histamine), had canned pineapple in juice (any food in a can would be high histamine from what I understand) and pasta made with canned tomatoes. Boy, it really clobbered me!     I had chills, racing heartbeat, felt very nauseous (but did not throw up that time) and had weird feelings in my limbs that are hard to describe (sort of a vibration but very mild - its like that feeling when you did lots of intense physical exercise and your really tired and your limbs feel weak). I also sneezed here and there - just single sneezes hours apart for no reason during my reaction - I felt funny for a few days. Sometimes people with a histamine reaction think they have the flu. It can do different things to different people and you don't always get the same reaction. I generally prefer fresh stuff, but sometimes in this winter weather its hard to get out and then I rely on "safe" canned stuff but did not expect the histamine problem.

Histamine builds up in the body if you eat too many foods high in histamine close together and then it clobbers you. Oddly enough I can eat yogurt and it doesn't seem to bother me any - I just found a safe plain yogurt and have been eating it daily. I say this because "fermented foods" should be high histamine from what I understand... yet yogurt is supposed to help the gut () so... Anyway, I recently found some plain stuff that is free of the stupid "natural Flavors" I react to.     Almost everything seems to have Natural Flavors added to it these days, even the stuff at the health food store.

Sometimes people on the paleo diet like I am run into this histamine problem. Due to soy, I'm pretty much forced to eat this way.

Soybean oil has also given me a throwing up feeling. I am allergic to soy and that was one of the things that helped me find my allergy.

I hope this gives you a new avenue to search for a possible answer.

I once read histamine problems are caused by a lack of enzymes but I don't know if that's true or not.

Ugh - it can be so hard to try and pinpoint the "maybe" reactions, huh?  Sometimes it helps me to ask myself, "If my kids didn't have allergies would I assume reaction?"

My body has an adverse reaction to raw carrots.  I don't have a texture problem with them, can chew them up just fine, don't Hate the taste, etc.  But, whenever I try to swallow, my gag reflex (which is very un-sensitive FWIW) kicks in, my eyes water, my face turns red and my throat clamps down.  It's almost impossible for me to swallow.  It's kind of scary when it happens.  Maybe your DS experienced something similar?  OR was he having any drainage down his throat?  That can make it hard to swallow certain textures of food.  Extra big bite since it was a "treat"?

Hopefully you'll be able to figure something out soon!

I double checked the donut recipe.  There is absolutely nothing in there I don't use on a weekly basis so I don't see what it could have been with 1 exception...he has always been averse to concentrated milk protein.  He doesn't usually drink milk, hates homemade whipped cream, vanilla ice cream, etc...The donuts had an exorbitant amount of butter. But he eats cheese and yogurt all day long so clearly not a serious allergy if it is one (milk allergy does run in my family).

The cookies. No idea but the coconut or maybe chocolate.  I have a mild issue with chocolate. That still leave me with 2 different culprits.

Not picky at all.  He eats spicy food and all kinds of stuff.  He later said the feeling was like he was going to throw up so I'm guessing bile came up his throat, because it was his throat that bothered him. 

It's my allergic kids who are picky, have sensory issues, etc...This kid throws his body around like a crash test dummy and seems to have no "other" sensory issues. 
Brownie

Ugh-- well, the only way you're really going to know is to go through identical ingredients in the donut recipe one at a time.

  I don't envy you this process, but yeah, it really could be totally non-allergic texture stuff.  Is he kind of a picky eater?

I have 3 boys.  The oldest is PA.  The 2nd is PA and TNA (as well as black beans and shellfish).  The youngest (7 yrs) has NKA.  Oddly, we thought he reacted to pumpkin seeds as a toddler, but the test was negative.  He eats peanut occasionally and once in a great while almond or walnut.  2 weeks ago, my oldest made homemade donuts....flour, way too much butter, sugar...the basics all from my kitchen, in my kitchen.  The 7 year old's eyes teared up and he started crying.  He was panicking.  OK - thought he didn't like all the butter or something.  The quantities were nauseating.  The donuts were plain vanilla, no icing.  And the donut maker was new.  Though I had wiped it down and thrown out the first batch, it seemed to have a stinky coating.  His stomach bothered him for hours.

Fast forward to today.  We tried GS cookies for the first time.  The youngest tried his first Samoa, my favorite, with wide eyes...and immediately his eyes turned red, watered up and he was freaking out.  We grabbed an epi and Benadryl but after drinking water he was fine.  I see nothing in common between the 2 items that wouldn't be in everything else we eat.  So maybe a coincidence?  Coconut allergy seems highly unlikely if he's not allergic to any of the top 8, right?

Baffled here...and not wanting to blow $1000 for negative allergy tests if he just doesn't like the texture of coconut, KWIM ?  But with the 2 experiences nearly back to back, I have to wonder if I'm missing something.

Thanks, Brownie