hello, welcome to HCM. As you are suffering from IBS
your symptoms could be associated to deficiency of several important vitamins and other factors which get deficient due to poor absorption in body. The most common thing is anemia
which in turn leads to increased fatiguability and tiredness
. You must get your blood work up done. And you must avoid heavy exercise for long periods. Avoid taking of alcohol and ciggarete smoking
. Take fresh fruits and vegetables. Wish you good health.