Your experience is not unusual. A retroperitoneal approach can commonly cause an ileus, This is where the intestines “go on strike” which causes abdominal discomfort, bloating, nausea, lack of passing gas and swelling of the belly. This can last for 2-4 days and food intake needs to be restricted. This will pass. Did you have a posterior instrumentation?
Donald Corenman, MD, DC is a highly-regarded spine surgeon, considered an expert in the area of neck and back pain. Trained as both a Medical Doctor and Doctor of Chiropractic, Dr. Corenman earned academic appointments as Clinical Assistant Professor and Assistant Professor of Orthopaedic Surgery at the University of Colorado Health Sciences Center, and his research on spine surgery and rehabilitation has resulted in the publication of multiple peer-reviewed articles and two books.