I have a gurgling sound when I press by my right hip and severe constipation. What could cause it?

Gas. Your colon has several parts: the ascending, transverse, descending, and recto/sigmoid areas. If you are severely constipated you likely have a fair amount of gas built up behind the lower part of your colon..Therefor the right lower quadrant of your abdomen may be full of backed up air or gas. Try routine over the counter measures for constipation, but if not relieved, talk to your doctor.