Hi, thanks for reading this. My new doctor just gave me a scrip for this med, Xifaxan, and admits she doesn't know much about it. I have IBS-C and chronic C. Last year my PCP gave this to me and it helped me more than any of the meds I had tried. Only problem is this new PCP isn't sure of the dosage for me. I'm in my 60s and know most of you are young folks but am hoping maybe some of you know of a situation involving an old gal like myself who has taken this. Thank you kindly! AnnahD