Irritable bowel syndrome (IBS) is known to be a heterogeneous disease, characterized by abdominal pain and disorders of intestinal motility. This study aims at investigating if serum calcium levels correlate with lipid values in IBS and the oxidant / antioxidant system as one of the factors proposed in the etiology of IBS. A total of 70 patient’s women with IBS were included in this study. 70 healthy subjects were selected to form the control group. Total cholesterol, triglycerides, calcium, Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-), superoxide (O2), carbonyls proteins (Pc) and malondialdehyde (MDA) and nitric oxide (NO) concentrations were studied in all patients and controls. The characteristics of the study population show that the mean age is 45 ± 3 and 47 ± 4 years for control women and IBS women respectively, as well as women with IBS is overweight Calcium significantly decreased while increasing total cholesterol and triglycerides in women IBS . MDA, carbonyls proteins, NO and O2 concentrations were significantly higher in IBS patients than in controls. The vitamin C, Catalase, SOD and GSH activities patients with IBS were significantly lower than that of controls. These results suggest that alterations in lipid profile, level of calcium and the oxidant/ antioxidant system may play a role in the pathogenesis of IBS.