What causes mixed hemorrhoids?

Mixed hemorrhoids are caused by constipation, prolonged defecation or long-term diarrhea, which can increase abdominal pressure, anorectal congestion, hemorrhoidal varicose veins, and even lead to rectal mucosa and muscle layer separation and prolapse, anal canal moving down with feces, and hemorrhoids are easy to produce for a long time. Or the defect of physiological structure and upright position, when the human body stands or sits upright, the anus position is low, the blood circulation of rectal anal vein is obstructed, the superior rectal vein and its branches lack venous valve, the blood is easy to produce stasis, and the rectal blood vessels are arranged specially, passing through the muscle layer at different planes is easy to be compressed by feces, so that the veins in the loose tissue under the mucosa are easy to expand and varicose and produce hemorrhoids.