Irritable Bowel Syndrome(IBS) is a set of symptoms that cause digestive distress. Symptoms include indigestion, gas, bloating, pain, constipation and diarrhea. Food intolerances such as gluten, lactose and fructose are often present. SIBO and SIFO(small intestine bacterial/fungal overgrowth) have similar symptoms and have been implicated as causes of IBS.