Take another look at the original sentence:
You wanted to fix it this way:
Although a comma and a coordinating conjunction like so can legally connect two main clauses, this correction method will not work in the example above. The problem is that so, a coordinating conjunction which shows result, does not join the two main clauses logically. Paola is not waiting to eat because her stomach is rumbling loudly.
You might want to consult the rules for fixing comma splices and fused sentences.