What a load of horsecrap, if you believe he is faking it do a simple physical exam, you cant fake a perf ulcer on an abd exam - the abd wall is rigid as a rock, minimal palpation sends them up the wall, likely decreased bowel sounds (although this is a highly subjective one and abdominal auscultation is of questionable yield).

At the end of the day, this person should have seen a physician, and regardless of her experience a nurse should always elevate complaints of sever pain to one.