Does anyone have a large belly before surgery?

Thank goodness I was warned about swelly belly. My uterus has lots of small fibroids but it's at least 12 weeks in size with a really thick lining. I thought I'd be skinny when everything came out, so I'm glad I know now that might not happen for a long time. I've been looking everywhere for a real explanation on what it is (since it mysteriously shows up sometimes months after the surgery). The only thing I found was a short statement "Abdominal distention may develop from the sudden release of pressure on the intestines when a large tumor (or uterus) is removed or from paralytic ileus secondary to anesthesia and pressure on the bowel."