Irritable bowel syndrome (IBS) is a common condition that affects the stomach and intestines, also called the gastrointestinal tract. Symptoms include cramping, belly pain, bloating, gas, and diarrhea or constipation, or both. IBS is an ongoing condition that needs long-term management. 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 medicine and counseling. IBS doesn't cause changes in bowel tissue or increase risk of colorectal cancer.