The occurrence of anorectal diseases is caused by a variety of factors, which can be divided into two categories: internal causes and external causes.
(1) Anatomical factors: There are a large number of special structures in the anorectum, such as anal recesses, anal glands, anal papilla, rectal valve and special vascular structures. There is a lack of venous valves in the rectal veins, and blood tends to pool. The portal vein and the vena cava are located at the lower end of the rectum. There are many venous plexuses and anastomoses. The vein wall is weak and the resistance to pressure is reduced. The submucosal tissue of the rectum is loosened, which is conducive to the expansion of varicose veins and the formation of hemorrhoids.
(2) Physiological factors: The colon and rectum are the main organs for transporting food residues and storing feces. After the food is decomposed and absorbed in the body, the residues often contain a lot of harmful substances, which can be retained in the colorectal for a long time and can induce tumors.
(3) Genetic factors: due to genetic defects, multiple colonic polyps, p-j syndrome (melanoma-colon polyposis) and other hereditary anorectal diseases can occur.
(4) Abnormal embryonic development factors: The anorectum is formed by the fusion of the endoderm and ectoderm during the embryonic development of the human body. If the development process is abnormal, many congenital anorectal diseases can occur in the anorectum, such as congenital anus Disease, congenital rectovaginal (urethral) fistula, congenital megacolon, etc.
(1) Poor defecation habits: When going to the toilet, squatting and reading the newspaper will cause the squat and defecation time to be prolonged. It is easy to cause blood stasis in the anus and rectum and induce diseases. Smoking while going to the toilet can buffer the brain's defecation reflex, which can easily cause constipation. Excessive force during defecation, some people, regardless of whether the defecation is strong or not, blindly and constantly strive hard, which can only increase the unnecessary burden of the rectal anus and pelvic floor muscles and local blood stasis, leading to the occurrence and development of the disease.
(2) Abnormal defecation: Diarrhea and constipation are both important pathogenic factors of anorectal diseases. Constipation is the biggest curse. Long-term retention of toxic substances in the rectum can not only induce rectal cancer, but also the accumulation of stool, which affects blood circulation. Exercising the dry fecal mass will inevitably cause a series of pathological changes such as blood stasis, swelling, and cracks in the anus. Diarrhea is often a clinical manifestation of colon disease. Diarrhea can also increase the chance of local infection in the anus, resulting in anal sinusitis, inflammatory external hemorrhoids, perianal abscess and other diseases.
(3) Dietary factors: In daily life, it is natural that the dietary pattern or diet variety will inevitably change. For example, the quality of food, changes in vegetable types and quantity, the amount of protein, fat, starch, cellulose, etc., and water intake can directly affect the composition of stool and cause anorectal diseases. People who drink alcohol or eat spicy food for a long time, because alcohol and spicy food can stimulate the mucous membrane of the digestive tract, causing vasodilation, colonic dysfunction, and anorectal diseases. According to the national census data, the incidence of spicy food is 61.6%, and the incidence of drinking alcohol is 64.6%, which is significantly higher than the overall incidence.
(4) Occupational factors: standing or sitting for a long time. The anus and rectum lie in the lower part of the human body due to the upright or sitting posture, and the hemorrhoid veins are not smooth.
(5) Chronic diseases: such as long-term malnutrition, weak physique, causing relaxation and weakness of the anal sphincter. Suffering from chronic bronchitis and emphysema for a long time, abdominal pressure rises due to cough and asthma, and pelvic blood stasis. Chronic hepatitis, cirrhosis, diarrhea, colitis, etc. are all triggers for anorectal diseases. Therefore, in prevention, attention should be paid to the patient's general condition and reasonable and effective preventive measures should be taken.