Irritable Bowel Syndrome (IBS) is the dysfunction of the lower part of the intestinal tract, which includes the lower part of the small intestine and the large intestine, i.e. too much contraction and get triggered easily by the things you eat such as spicy food, tea, coffee, or sometimes stress. Irritable bowel syndrome is characterized by cramping or stomach discomfort, sometimes accompanied by changes of bowel movement such as constipation or diarrhea. Symptoms tend to come and go in episodes, but may not disappear completely.