In the past, the only breath test I knew of that also tested for methane was at the Great Smokies Diagnosic Lab.http://www.gsdl.com/home/assessments/bacterial_overgrowth/After reading Mark Pimentel's new book, "A New IBS Solution", I came across another lab that the author actually recommends called the QuinTron Instrument Company in Milwaukee, WI.http://www.quintron-usa.com1-800-542-4448The author recommended that you call this number to find a physician in your area that uses their equipment. If you can't find someone close by or who doesn't accept your insurance you have another option. The Lab will actually mail you the breath test to take at home. All you need is for your doctor to call the number and fax over a prescription and the test will arrive at your doctor's office. As far as I know, this is free for you since insurance will likely cover it. I'm going to see my doctor tomorrow and request a test so I'll keep you up to date. It's recommended you also take this test after you are done with your anti-biotics to make sure most of the offensive bacteria is eradicated.