Irritable Bowel Syndrome (IBS) is often linked to bacterial/parasitic/fungal/viral overgrowth of the intestines. Discovering and eradicating the overgrowth can improve IBS. Other things to consider are food sensitivities that can cause bloating, constipation, diarrhea, and abdominal cramping. IBS can also be linked to insufficient probiotics and digestive enzymes. The standard American diet, loaded with processed/genetically modified/sugary/pesticide laden foods can contribute to bowel issues.