Internal hemorrhoids: located above the dentate line, formed by the expansion and flexion of the venous plexus within the hemorrhoid, the surface is covered with mucous membrane. There are four stages of internal hemorrhoids according to their severity: 1. It is mostly related to diet and dryness of stool. The mucous membrane is visible under the anoscope as a limited nodular elevation, soft and red in color. During finger examination, the mass is usually not easily palpable and the mucosa is smooth. 2.Stage II internal hemorrhoids: There is intermittent blood in the stool, with blood or dripping blood, bright red blood, and during the attack, there is anal swelling and a feeling of urgency. Due to the enlargement of hemorrhoid nucleus, the hemorrhoid is prolapsed out of anus by the impact and extrusion of stool, but it can be returned by itself after stool. Under anoscopy, the mucous membrane is thickened and the surface of the hemorrhoid nucleus is purplish-red, with a small amount of discharge and some bleeding easily when touched. During finger examination, some soft masses can be palpated. 3.Stage III internal hemorrhoids: The volume of the nucleus increases, there is connective tissue hyperplasia, the mucosa thickens, at this time it is not easy to bleed, such as mucosal rupture, bleeding more, dripping blood, shooting blood. The mucosa is pale or slightly red, and the surface is rough. Some surface erosion oozing blood, if the anal canal moves down, the mucosa can protrude outside the anus. After prolapse, it cannot be returned by itself and needs to be pushed back by hand or reset after lying down. If the hemorrhoid nucleus is often prolapsed, it will easily lead to the relaxation of the anal sphincter muscle, which can cause the hemorrhoid nucleus to prolapse when encountering force, coughing, walking, squatting or energy distraction. 4, embedded internal hemorrhoids: If the nucleus of the hemorrhoid is prolapsed and embedded can not be sent back in time, due to the spasm of the sphincter muscle, resulting in blood back to the fluid obstruction, so that the nucleus of the hemorrhoid is congested and edematous, thrombosis, severe pain, restlessness, surface discharge, and even surface ulceration, necrosis. This is an acute attack of internal hemorrhoids, called embedded internal hemorrhoids or internal hemorrhoid impaction.