Intestinal vascular malformations include arteriovenous malformations, vasodilatation, hemangioma, and vascular dysplasia, etc. They are one of the causes of acute or chronic lower gastrointestinal bleeding, and are often abnormalities of the blood vessels themselves, or may be a manifestation of a systemic disease or a syndrome. The etiology and pathogenesis of this disease are not yet fully understood, and it occurs in the jejunum, cecum and right hemicolectum. The main clinical manifestations of patients are gastrointestinal bleeding and secondary anemia. The pathological changes are submucosal inter-arterial traffic, arterialization of veins, thickening, dilatation, distortion and sclerosis of the vein wall. It occurs mostly in the rectum and sigmoid colon and is often associated with cardiovascular disease, peripheral vascular disease and aortic stenosis; it is acquired secondary to certain diseases, such as portal hypertension enteropathy, degenerative degeneration of submucosal vein wall in the elderly with chronic constipation, so that the submucosal veins penetrating the muscle layer of the intestinal wall are repeatedly compressed by muscle contraction, resulting in increased intravenous luminal pressure, venous dilatation, hypocapillary pre-capillary sphincter function, and functional arteriovenous communication. The arteries communicate directly with the veins, forming a functional arteriovenous fistula. Small bowel vascular malformations often occur in conjunction with colonic vascular malformations.