Crohn’s disease (Crohn’s disease) and ulcerative colitis are the two predominant inflammatory bowel diseases (IBDs), and both are characterized by recurrent episodes of inflammation of the intestinal mucosal surfaces. At the same time, the extraintestinal manifestations of IBDs are complex processes that can coexist. The progression of disease in IBDs is unpredictable and sometimes life-threatening. Colorectal cancer is a complication of inflammatory bowel disease for which the evidence is clear and requires close patient follow-up. It has also been demonstrated that elevated susceptibility to inflammatory bowel disease is associated with certain genetic and environmental factors, such as smoking, and that these factors play a key role in the development and activity of the disease. In a case-control study of patients with Crohn’s disease and ulcerative colitis in Stockholm, it was found that increased fiber intake was negatively correlated with the development of the disease. In addition, coffee intake greatly reduced the risk of disease progression. The relationship between exposure to certain environmental factors and disease was observed in a prospective cohort study of patients with IBD conducted in Australia, and the results suggested that caffeine intake had a protective effect in patients with ulcerative colitis. (OR 0.51 [ 95% CI 0.30-0.87], p=0.002). In addition, the study found a weak negative correlation between morbidity and caffeine intake in patients with Crohn’s disease (OR 0.59 [ 95% CI 0.34-1.03], P=0.031). In both diseases, no adjustment for confounders was made. Contrary to the previously discussed results is the study by Halfvason et al: whose study examined the pathogenesis of environmental factors influencing intestinal inflammation in twins, in their study they found an opposite relationship between coffee intake and disease occurrence, and when corrected for smoking, the results were again not statistically significant. In addition, the study by Boyko et al. did not find a significant correlation between coffee intake or cumulative coffee intake and the development of ulcerative colitis. Conclusion Coffee intake has a protective effect against ulcerative colitis; there was no significant correlation between coffee and Crohn’s disease.