HI. I'm a 66 yr old with MAC, Bronchiectasis and Congestive Heart Failure. (from one of the chemo drugs used to treat my breast cancer 5 years ago). So when it came to deciding whether to treat my MAC, discovered 2 years ago, I sort of freaked out thinking about taking more meds with some bad side effects. I had gut problems from just taking a 5 day pack of Azithromycin in the past. Because I live on a small island in Hawaii, and wanted to get the best consultation I could, I flew to National Jewish Health in Denver. They are so comprehensive and actually reassuring. Possibly the best advice they gave was to take a probiotic Jarro-dophilus, twice a day to offset any gastrointestinal problems. It really works. You can get it at Whole Foods or online from The Vitamin Shop. The great thing about it is that it doens't need to be refrigerated. I've been on Ethambutol, Azithromycin and Rifabutin for 2 years now. Going off next month. I stayed on a little longer than normal because I have no sputum and didn't want a bronch with my CHF. The last sputum I had (4 mos ago) was negative for MAC. While on the drugs I had my eyes checked every 2 months and labs every month for liver or kidney damage. I feel that I owe everything to this silly little pro-biotic that has managed to keep me as normal as possible and yeast infection free during the entire treatment time. Hope this helps anyone out there having a hard time tolerating the MAC meds.