This study wants to see if the medicine colchicine can help lower inflammation and reduce the chance of developing an irregular heartbeat (atrial fibrillation) after heart bypass surgery. Adults having coronary artery bypass surgery (CABG) can join. Participants will be randomly placed into one of two groups: one group will receive colchicine along with usual care, and the other will receive a placebo (a look-alike capsule with no medicine) along with usual care. Everyone will take a study capsule, and neither the patients nor the study team will know which capsule is being given. Everyone in the study will take study capsule, and neither the patients nor the study team will know who is receiving colchicine or placebo. Blood samples and health information will be collected before surgery; at 24, 48, 72, and 96 hours after surgery; and again at 10 days after surgery or at hospital discharge, whichever comes first. The investigators will look at inflammation marker levels, whether atrial fibrillation happens, and any side effects. This small study will help to generate effect size estimates and safety data that will help plan a larger study in the future.