Thank you for your question. Abdominal swelling is normal after breast reduction. Swelling follows gravity and thus your abdomen (and sometimes the thighs) will experience more swelling and add confusion to the post-op period. You may even notice that you've added many pounds on the scale despite the reduction in breast size. You should notice a decrease in the abdominal swelling with each week that passes by.
Almost any surgery which is conducted under general anesthesia can result in post-op ileus, or alteration in the normal function of the gastrointestinal tract. How long was your procedure? How long did you take post-op pain pills? What type pain pills were prescribed? What activity schedule are you currently observing? Post-op factors which can make any woman "irregular" include general anesthesia, pain tablets, pain, uncertainty, dehydration, antibiotics, etc. Consult your PS and ask whether the addition of probiotics, warm teas and gradual resumption of activity may be useful in resolving your bloat. Gas-X or Bean-O may also be useful. Good luck.