IBS problem. There any therapy for this?

I'm facing the problems of IBS apparently since 7 yrs now. When consulted a doctor, he said there is no permanent cure for this, is it true? Off late, this problem has become even more serious. Due to my work life, I'm forced to eat out i.e my lunch, evening snacks and dinner at times. On account of this since few days I've been facing problems of indigestion due to which I'm having home food but when I'm hungry and try to eat my tummy feels full and later i feel lot hungry and the cycle repeats. I feel weak these days. Unable to resume office or perform any other activity due to lack of energy. I visited couple of doctors but the cure was short term. I wanna know with this kind of work life, how to improved the power of digestion. Is there any therapy for this?