Abstract Background Irritable bowel syndrome (IBS) is the most common functional gastrointestinal disorder characterized by the presence of abdominal pain, bloating and altered bowel habits. The pathophysiological mechanisms underlying IBS are unclear. The abnormalities of motility, visceral hypersensitivity, gut microbial alteration and psychological stress contribute to the clinical symptoms of IBS. The associations of IBS and its risk gene polymorphisms have been ascertained by many researchers. Single nucleotide polymorphisms (SNPs) represent the most widespread type of sequence variations in genomes. It is known to be valuable genetic markers, because it may reveal the evolutionary history and common genetic polymorphisms that explain the hereditary risks for common diseases. Cytokines are involved in the pathogenesis of IBS. To date, only a few studies concerned the association of interleukin-10 (IL-10) gene polymorphism (rs1800871) -819 position to IBS. Objective We assessed interleukin 10 (IL-10) single nucleotide polymorphism rs1800871 (-819 C/T) in IBS patients. Method This was comparative case - control study for 40 participants, 20 cases and 20 controls, IL-10 rs1800871 (−819 T/C) single nucleotide polymorphism (SNP) was done via real time polymerase chain reaction for both study groups to assess its relation with IBS. Results The studied participants were divided into two groups according to ROME IV _criteria. For the case group (n = 20), the mean age was 41.05 ± 17.45 years, with 50% being male and 50% being female. In the control group (n = 20), mean age was 39.80 ± 14.84 years, with 25% being male and 75% being female Compared to the controls subjects, the frequencies of the IL-10 -819 T/T genotype and T allele were observed to be overrepresented in patients with IBS (60%; odds ratio [OR] = 1.143; 95% confidence interval [CI]: (0.152 – 8.593) for the TT genotype; P = 0.897) and (72.5%; OR: 1.582; 95% CI: (0.615 – 4.066)for the T allele; P = 0.341, respectively). The results demonstrated that T/T genotype was the most common genotype in the case group (60%). T allele was the most prevalent in case group (72.5%), while the C allele was the least prevalent (27.5%). However, T/T polymorphism in cases was greater than in control with non- statistical significance (p = 0.157). Conclusion IL-10 polymorphism (rs-1800871) has no association with IBS, However, T/T genotype was shown frequently in cases, with strong association with IBS. Abbreviations: IBS (irritable bowel syndrome), IL-10 (Interleukin-10 cytokine), SNP (single nucleotide polymorphism)