1.What diseases belong to the scope of anorectal treatment?
Various diseases of the anus, rectum and colon all belong to the scope of anorectal medicine. Common anal diseases include internal and external hemorrhoids, anal fissure, anal fistula, prolapse; colon diseases include ulcerative colitis, colon polyps, colonic diverticulitis, colon tumors, rectal prolapse, etc. In addition, such as anal eczema, anal pruritus, acral warts, various congenital anorectal malformations also belong to the category of anorectal diseases.
2.What factors are related to the occurrence of anorectal diseases?
The occurrence of anorectal diseases is caused by a variety of factors, which can be summarized into two categories of internal and external causes.
Internal factors.
(1) anatomical factors: the anorectal department has a large number of special structures, such as anal fossa, anal glands, anal papillae, rectal flaps and special vascular structures, such as the lack of venous flaps in the rectal veins, the lateral branches of the portal vein system and the vena cava system anastomosing at the lower end of the rectum, and the vascular cushion tissue on the dentate line, which easily cause common anorectal diseases such as hemorrhoids and anal fistulas.
(2) Physiological factors: the colon and rectum are the main organs for transporting food residues and storing feces, and the residues of food decomposed and absorbed by the body often carry a lot of harmful substances, which can induce tumors if they are left in the colon and rectum for a long time.
(3) Genetic factors: Due to the defects of genetic genes, multiple colon polyps, P-J syndrome and other hereditary anorectal diseases can be produced.
(4) Abnormal embryonic development factors: the anorectal part is the result of mutual fusion of endoderm and ectoderm in the human body during embryonic development. If the developmental process is abnormal, many congenital anorectal diseases can be produced in the anorectal department, such as congenital anorectal syndrome, congenital rectovaginal (urethral) fistula, congenital megacolon, etc.
External causes.
(1) bad defecation habits: reading books and newspapers in the toilet, resulting in prolonged squatting and defecation time, which can easily cause stasis of blood in the anorectum and induce disease. Smoking in the toilet can buffer the brain’s defecation reflex, which is very likely to cause constipation. Excessive force during defecation, some people do not care whether the feeling of defecation is strong, blindly and constantly fierce efforts to earn, can only make the rectum anus and pelvic floor muscles increase unnecessary burden, leading to the occurrence and development of disease.
(2) defecation abnormalities: diarrhea and constipation are important pathogenic factors of anorectal disease, constipation is the biggest bane, prolonged retention of toxic substances in the rectum can not only induce rectal cancer, and the accumulation of feces, affecting blood circulation, forceful solution of dry feces, will certainly make the anus under greater pressure to produce bruising, swelling, fissures and a series of pathological changes. Diarrhea is often a clinical manifestation of colon disease, diarrhea can also increase the chance of local anal infection, producing anal sinusitis, inflammatory external hemorrhoids, perianal abscesses and other diseases.
(3) Dietary factors: It is natural that dietary patterns or dietary varieties inevitably change in daily life. For example, the quality of food coarse and fine, the change in the type of vegetables and the amount of increase or decrease, the amount of protein, fat, starch, fiber and other content, water intake, can affect the composition of feces in the rectum, causing anorectal diseases. The incidence of anorectal diseases has increased significantly due to the long-term consumption of alcohol or spicy food, which can stimulate the mucous membrane of the digestive tract and cause vasodilation and colon dysfunction. The national survey data prove that the incidence rate of spicy food is 61.6%, and the incidence rate of wine drinkers is 64.6%, which are significantly higher than the total incidence rate.
(4) Chronic diseases: such as long-term malnutrition and weakness, causing the anal sphincter to relax and become weak. Long-term chronic bronchitis, emphysema, rising abdominal pressure and pelvic stasis caused by coughing. Chronic hepatitis, cirrhosis, diarrhea, colitis, etc. are all triggers for the occurrence of anal diseases. Therefore, in the prevention should focus on the whole party state of the patient to select reasonable and effective preventive measures.
3.Why is anorectal disease a common and frequent disease?
Anorectal disease is a general term including anal, rectal and colonic diseases, which is a common and frequent disease in daily life. There is a common saying among our people that “nine out of ten people have hemorrhoids”, which is enough to explain the problem. Anal diseases can affect both men and women, and can develop in adults and infants, and national census data show that the incidence of anorectal disease in adults is about 60-75%, with a higher incidence in rural adults than in urban adults. Although less life-threatening, the more serious cases often affect normal work and life, and even the less serious cases have to endure the pain of the disease from time to time. Some infants suffer from anorectal disease, which not only affects their development and growth, but also causes a great burden to their parents. Thus, we should pay attention to the prevention and treatment of anal diseases.
4.Where is the anus located?
The anus is the opening at the end of the digestive tract that leads to the outside of the body and is located on the midline of the buttocks, between the center of the perineum and the tip of the tailbone. It is normally closed in a front-to-back longitudinal fissure and expands in a round shape when defecating, with a diameter of about 2 to 3 cm.
5.What are the tissues that make up the anal canal? What is the clinical significance?
The anal canal is located below the rectum and above the anal verge. One is called anatomical anal canal, which starts from the anal verge and ends at the dentate line and is about 2.5-3 cm long. The surface of the anal canal is metastatic epithelium surrounded by some of the internal and external anal sphincters and joint longitudinal muscles.
The other type is called the surgical anal canal, which starts from the anal margin and ends at the level of the anorectal ring about 1.5 cm above the dentate line. Its length is about 4.2 cm, and its wall is surrounded by all the internal and external sphincters, the joint longitudinal muscle and the anal levator muscle, which is also called the sphincter anal canal. The difference between anatomical and surgical anal canals is whether the terminal rectum is included in the anal canal. Although the former division has its morphological basis, the clinical application is more limited; the latter takes the clinical need as the starting point and considers it as the main tissue structure for controlling normal defecation, which provides some convenience for clinical treatment, but because the terminal rectum is included, it brings inconvenience to the classification of diseases.