Hi, I am new to this forum. I started the Big 3 around two months ago at the initial MAC diagnosis. Some people are for taking the drugs, some say, lets watch the progression of the disease and start the Big 3 when the infection gets worse. I do understand both arguments. For me the answer is rather simple. If these drugs do not work now, they will definitely not work if/when my health worsens in the future. I do live in a very stressful environment and so I am not keen on taking chances when it comes to my health. To answer your question: when I started, I took them all together and had terrible diarrhea and stomach cramps in effect. It was really bad. I work in a very public, exposed environment, so you can imagine what I went through. I started taking Imodium. It helped a bit, but it definitely was not the solution. The doctor then told me to take ethambutol on empty stomach in the morning and rifampin + azithromycin at night before going to bed (and take Imodium half an hour before). I experience no diarrhea or stomach cramps if I take the Big 3 in this way.