Plasma levels of globulin [ ( 24.12.4 ) g/L vs. ( 22.13.3 ) g/L , P < 0.05 ] , immunoglobulin G [ ( 10.82.4 ) g/L vs. ( 8.72.1 ) g/L , P < 0.01 ] and complement 4 [ ( 0.240.09 ) g/L vs. ( 0.170.05 ) g/L , P < 0.05 ] on postoperative day 3 were higher in early oral feeding group as compared to conventional oral feeding group .