Curiously enough, many people are shocked to learn that fatigue is a common symptom of Irritable Bowel Syndrome. However, fatigue stands as one of the top extraintestinal symptoms associated with IBS. Fatigue is best described as a sensation of extreme tiredness, exhaustion, or lack of energy. It is normal to feel slightly fatigued after a bad night’s sleep, or a bout of intense physical exertion. However, many illnesses cause abnormal fatigue that must be addressed by a medical professional. If fatigue occurs in conjunction with other more severe symptoms, or if it lasts more than two weeks without apparent cause, a visit to the doctor is highly recommended.