Do not believe that IBS does not cause health problems later on. Sometime in the last decade I developed osteomalacia. This is a condition caused by a lack of Vitamin D. In adults (mostly women) it is usually associated with people who are bedridden or invalid, and get no sunlight. I have been an avid gardener and regular exerciser all my life, so I certainly do not fit that scenario. Yet I became sicker and sicker, honestly thought I would be dead in a year or so. After deciding through internet reading that I suffered from malabsorption, I went to a doctor stating such and was tested for vitamin D deficiency, which I had. I have never been diagnosed with Crohns or celiac disease or any other disease that would have put me at risk for a malabsorption related disorder. But I suffered from constant diarrhea for over 30 years. I am still seeking medical help to try and determine if the other problems I suffered heart arrythmia (mitral valve), blurred vision, numbness in feet and hands, Reynauds, migrains, even symptoms of dementia, that came and went over the years. There is more to IBS than what is presently known. I suspect that the chronic diarrhea plays havoc on your electroylytes and does affect the way the body absorbs nutrients and minerals.
If you suffer from IBS, I would advise having your basic body elements, calcium, phosphorus etc. checked regularly. I think I would not be stuck with aching bones, and years of underproductivity if I had been monitored more carefully instead of being written off as a whiner.
One light at the end of the tunnel: After menopause, the IBS stopped. However, that is when the serious bone pain developed in my hip and now in my legs despite being treated with a weekly dose of Vitamin D. My calcium levels were probably low for years (I'm also lactose intolerant) causing secondary hyperthyroidism.
Any disease that causes this much interruption in a life should be given more credibiltiy than it gets. But it won't kill you overnight, and it has few mechanical manifestations so doctors have nothing concrete to treat. This makes you an unpopular patient. Try to find a doctor who at least will acknowledge that a person with healthy organs and healthy bloodwork who none the less undergoes chronic, horribly painful bouts of severe diarrhea, and nausea, and a series of other unrelated non life threatening health irregularities, may have a problem that the medical community has yet to diagnsose. That is something anyway, but all I can say is good luck with that.