Fatty liver and colorectal tumors seem to be two completely unrelated diseases, but studies have found that the incidence of colorectal tumors in patients with fatty liver is quite high, and they found a 34.7% incidence of colorectal adenomas in 199 patients with fatty liver aged 40-70 years. It has been well known that non-alcoholic fatty liver (fatty liver for short) is often accompanied with high blood lipids, high blood sugar (diabetes) and high blood pressure (cardiovascular disease), while fatty liver and colorectal tumor seem to be two completely unrelated diseases. However, Chinese scholars in Hong Kong reported in recent years that the incidence of colorectal tumors in patients with fatty liver was quite high. They found that the incidence of colorectal adenoma was 34.7% and the incidence of progressive colorectal tumors (including colorectal cancer, villous adenoma or highly heterogeneous hyperplasia) was 18.6% in 199 patients with fatty liver aged 40-70 years, which were respectively higher than those in healthy control population (181) without fatty liver (21.5%). nearly twice (21.5%) and more than three times (5.5%) higher, while the incidence of colorectal adenomas and progressive colorectal neoplasms was as high as 51% and 35%, respectively, in patients with pathologically confirmed steatohepatitis. Data from Hong Kong and Austrian sources confirmed, after statistically excluding other factors, that fatty liver was independently associated with the occurrence of colorectal adenoma and progressive colorectal neoplasm. In contrast, scholars from Korea and Ningbo, China confirmed that precancerous lesions such as adenomatous polyps of the large intestine were significantly associated with fatty liver from another perspective. They found that the concomitant incidence of fatty liver in patients with adenomatous polyps of the large intestine was as high as 41.5% and 32%, respectively, in the physical examination population, while the detection rate of fatty liver was 30% and 20% in the population without polyps, both of which were significantly different. Scholars coincidentally agree that fatty liver, especially in patients with steatohepatitis, is a high-risk group for colorectal tumor-like changes, especially progressive colorectal tumors, and should be taken seriously. The exact reasons for the high incidence of colorectal tumors or tumor-like changes in patients with fatty liver are not fully understood, but may be related to the common poor lifestyle, especially the high-fat, high-calorie, low-fiber diet and insufficient physical activity, while the excessive visceral fat and its metabolites in patients with fatty liver can stimulate the body to produce a variety of inflammatory factors, stimulating chronic inflammation and tissue damage in multiple organs, including the large intestine. The formation of a tumor-prone microenvironment eventually leads to the development of tumors. Animal experimental data have also confirmed that visceral fat deposition has significant lipotoxic and pro-cancer properties. Epidemiological data clearly show that fatty liver is closely related to the occurrence of colorectal tumors, and due to the influence of various factors, the incidence of fatty liver in China has been increasing in recent years, and the related colorectal tumors may also be rising, which is bound to pose a greater threat to the health of the population. In fact, according to the statistics of the Center for Disease Control and Prevention, the incidence of colorectal cancer has increased from 12/100,000 in the 1970s to 56/100,000 at present, up 3.67 times, with an average annual growth rate of more than 4%, becoming the second place in the list of common malignant tumors.