If you have irritable bowel syndrome, or IBS, you might have uncomfortable or painful abdominal symptoms. Constipation, diarrhea, gas and bloating are common IBS symptoms. IBS doesn’t damage your digestive tract or raise your risk for colon cancer. You can often control symptoms through diet and lifestyle changes. These problems cause your digestive tract to be very sensitive. They also change how your bowel muscles contract. The result is abdominal pain, diarrhea and constipation.