If you do not suffer from fructose malabsorption then it does it matter if HFCS is the first, middle or last ingredient it probably won't act as a trigger.
If you do suffer from fructose malabsorption then it could matter. Some individuals cannot tolerate one excess gram of fructose (about 1/5 tsp) while others can handle a quite a few grams. Furthermore, fructose problems can be accumulative. For example, eating a small amount of excess fructose a couple of times a day for a few days can produce pain, gas and bloating.
-------------------- STABLE: ♂, IBS-D 50+ years - Science of IBS