Irritable Bowel Syndrome (IBS) might not be evidently different from stomach upset as far as many people are concerned. It is, however, one of the more painful gastrointestinal conditions known to man.
It is not easily narrowed to a singular cause, as the symptoms are in tandem with known stomach ailments. IBS can occur with constipation or with diarrhea. The occurrence of IBS with other ailments gives it the coloration of an indistinct ailment.