Irritable bowel syndrome (IBS) is a common disorder that affects the stomach and intestines, also called the gastrointestinal tract. Symptoms include cramping, abdominal pain, bloating, gas, and diarrhea or constipation, or both. IBS is a chronic condition that you'll need to manage long term. Only a small number of people with IBS have severe symptoms. Some people can control their symptoms by managing diet, lifestyle and stress. More-severe symptoms can be treated with medication and counseling. IBS doesn't cause changes in bowel tissue or increase your risk of colorectal cancer.