Hi J.,
My son has had acid reflux and GERD since infancy and has also had recurring bouts of croup, despite the fact that he's nine. (True croup is meant to stop during toddlerhood.) He's currently waiting for the gastroenterologist to take a look down his esophagus because - and here's the important part - that 'croup' may actually be a very particular type of asthma caused by micro-particles of regurgitated stomach contents being inhaled. The continued inhalation of these micro-particles can cause an allergic reaction in the trachea. It requires a different treatment than 'traditional' asthma.
The treatment is simple, if this is the case. My son will take an inhaler -- looks the same as his asthma inhaler -- only this steroid is not inhaled, it is actually 'gulped.' The pediatrician said that if my son ends up with this treatment then it will take some getting used to. For those of us who've spent years training ourselves how to 'puff' an inhaler, it's apparently kind of tricky to re-train ourselves to 'gulp' the mist. But, hey, sounds like a comparatively small obstacle.
My son remains on Losec, at the maximum dose for his weight. In some cases, this dosage can provide enough relief that the inflammation of the valve will cease (it becomes paralyzed when too irritated, allowing spontaneous regurgitation).
Sadly, in my son's case, it has not healed and appears to be a physical malformation. His problem may require surgery later on. But in your son's case, it may work.
Discuss all of this with his pediatrician and, if you feel he needs it, insist upon a referral to a gastroenterologist as soon as possible. Three of my four kids have this problem to one extent or another (my son is worst with reflux, but he has a sister who's even worse with croup). I feel your pain!
If you Google "GERD asthma" you'll get a number of informative articles, though many of them are not precisely the same as what was explained to me (which I have repeated here). I'll just have to wait and see if any of it leads to an effective solution for my little tribe. Hope it does for yours!
Best of luck and hang in there! :-)
PS: Sorry! Forgot: Symptoms of acid reflux! Your child is old enough to be able to speak and tell you when and where it hurts - huge help! Listen for complaints of 'sore' or 'burning' throat at the mention of stressful things - during or after tantrums or even simple things like doing something he finds unpleasant.
Ask how his pain feels: like a poke, a pinch, a splinter, a scraped knee, or like when someone's pressing on your bruise. My kids usually use the 'scraped knee' feeling to describe acidic tummies, often accompanied by the 'bruise' feeling.
Don't suggest, ask general open-ended questions. Act casual when he complains of his tummy burning; I've found that if I show worry, it makes the acid flow faster. A sip of baking soda water will take the edge off it - you'd think a toddler would never drink it, yet in my little guys the relief always outweighed the foul taste. That's a really clear sign of an acid tummy right there! And it only takes a tiny bit. Not a cure, though.
For GERD, look for lots of 'chewing the cud,' spitting, or what appears to be 'hocking up a loogie.' It's often actually spontaneous regurgitation. Not a fun thing. Have a look at it and give a sniff to determine its origins - also not fun.
Talk to your doctor after you compile a bit of information from your son over a week or so. Make notes on your calendar and take note of which foods/activities/situations increase your child's discomfort. It will all help your doctor to make a quick and accurate diagnosis instead of playing a two-month guessing game. :-)