Background: Irritable bowel syndrome (IBS) is a functional gastrointestinal (GI) disease that can change a patient's quality of life and impair his daily activities. Non-alcoholic fatty liver disease (NAFLD), on the other hand, has become a widespread condition as the global obesity rates rises. The prevalence of NAFLD has reached up to 25% of the adolescent population. The etiology of both diseases is still not clearly understood. The mechanism linking the two seemingly similar diseases could be immune system activation and tissue inflammation. Objective: The goal of our study was to see if there was a common link between them and to examine NAFLD prevalence and severity in IBS patients. Patients and methods: Our study included 150 patients who had symptoms of IBS with different degrees of severity. IBS was diagnosed according to modified ROME IV criteria. Patients were examined to see if they had NAFLD based on abdominal ultrasonography and NAFLD fibrosis score calculation. Results: Our current study showed that regarding evaluating the association of IBS with NAFLD, there was a highly statistically significant association between both diseases. Furthermore, there was a high statistically significant association between higher grades of NAFLD and lipid profile parameters. Conclusion: Patients with IBS had a higher frequency of NAFLD. In addition, a significant association was noted between IBS severity and increased NAFLD grades.