HFCS is a no-no only if you have fructose sensitivity.
Would you say honey is a no-no for IBS? Because honey is as troublesome as HFCS (it's another high fructose thing, potentially worse than HFCS in that regard)... the fact it's "natural" and has a "from the countryside" appeal does not make it OK.
Most people are not fructose intolerant/sensitive, thus most people should do fine with HFCS in moderate quantities (also with honey, fruit, etc in moderate quantities, LOL). Of course HFCS often comes with things like carbonated soda (bad because of the carbonation) or fatty items (bad because of their fat content), or items with high IF content. The HFCS, however, is usually not the problem in those items. Unless you are fructose sensitive, of course.
Again, HFCS avoidance has a price. You have to think about it and weigh whether it's worth avoiding it if you are not sensitive to it.