Anal canal sphincter spasm

　　Etiology

　　1. The absence of intestinal ganglion cells in the intestinal wall. The weakness of the rectum and the abnormality of the nerves supporting the anal canal internal sphincter are a special type of ultra-short megacolon.

　　2. Long-term neglect of defecation sense. When the rectum reaches a certain amount of stool and its internal pressure increases, defecation sense will occur. Defecation sense is a kind of somatosensory and visceral sensation produced in the cerebral cortex through the nervous system when the rectum is distended. If defecation sense is neglected, it will cause the external anal sphincter to contract, thereby exciting the contraction of the internal anal sphincter, and reflexively causing the relaxation of the rectal wall and the decrease of internal pressure. Long-term neglect of defecation sense will make this reflex become a habit, leading to spastic contraction of the internal anal sphincter.

　　3. Organic changes such as hypertrophy and fibrosis of the anal canal internal sphincter due to long-term spastic contraction can also lead to functional changes transforming into organic changes.

　　This disease is mainly caused by the narrowing of the intestinal lumen, causing corresponding complications of digestive tract obstruction. When severe constipation occurs, symptoms such as abdominal distension, abdominal pain, nausea and vomiting, and defecation disorders may occur. In severe cases, it can lead to impairment of blood supply to the intestinal wall, followed by intestinal necrosis. If not treated actively, it can lead to death. Severe vomiting patients may develop metabolic alkalosis due to the loss of a large amount of gastric juice, so it is necessary to dynamically monitor blood gas analysis and electrolytes to prevent electrolyte disorder and acid-base metabolism imbalance caused by excessive vomiting.

　　The main symptoms are painless defecation difficulty, faint defecation sense or no defecation sense, dry stool. Some patients have a sense of acid and胀in the perineum. The anal-rectal examination shows increased elasticity of the internal anal sphincter, which may be tender. The anal canal pressure increases, and it is even difficult to enter the anal canal with the tip of the finger. There is a large amount of stool accumulated in the rectum.

　　The etiology of this disease is unclear, and it cannot be prevented directly. However, dietary fiber is very important for changing the nature of stool and defecation habits. The fiber itself is not absorbed, it can cause the stool to swell, stimulate colonic motility, and is conducive to promoting defecation and reducing the occurrence of spastic contraction of the anal canal internal sphincter. This may be more effective for patients with less dietary fiber intake. The food with the most dietary fiber is bran, followed by fruits, vegetables, oats, corn, soybeans, pectin, etc. If there is fecal impaction, the stool should be evacuated first, and then dietary fiber should be supplemented.

　　First, defecation imaging:

　　1. The anal canal is not open, the rectal neck presents a symmetrical cystic expansion, and there is a radish root-like change at the anal-rectal junction;

　　2. The resting rectal expansion is significant, even leading to megarectum;

　　3. Barium cannot be completely evacuated.

　　Second, anal-rectal pressure measurement:The resting pressure of the anal canal is mainly maintained by the internal anal sphincter, so the resting pressure of patients with this disease is significantly higher than normal. In addition, the amplitude of the IAS relaxation reflex decreases or cannot be elicited, which has a definite significance for diagnosis, manifested as the pressure in the anal canal does not decrease significantly or even increases when the rectum is expanded by the balloon.

　　The maximum tolerance of the rectum is significantly increased.

　　Four, pelvic floor electromyography:The discharge frequency and interval of the internal anal sphincter electromyogram, as well as the presence or absence of electrical rhythm suppression during rectal dilation, are of great significance for the diagnosis of this disease and the differentiation of other outlet obstructive constipation.

　　1. Sweet Potatoes

　　Eating sweet potatoes can treat constipation, make defecation smooth and easy, and there is much experience in folk. 'Ben Cao Yuan Yuan' also records that sweet potatoes: 'Cool blood and activate blood, broaden the intestines, relieve constipation, and remove old blood stasis and internal toxins.' It is especially suitable for chronic constipation. You can also eat 250 grams of fresh sweet potato leaves, stir-fried with oil and salt, eat it all at once, once in the morning and evening on an empty stomach, suitable for people with dry and hard stools.

　　2. Mung Bean Paste

　　It can nourish yin and blood, moisten the intestines, and is suitable for people with physical weakness and constipation. The 'Renzhai Zhi Zhi Fang' introduces: 'For elderly people with constipation, two ounces of mung bean paste, three slices of white scallion roots, two spoons of honey, boiled water, remove the scallion, add mung bean paste and honey, dissolve and take before meals.' This method is also suitable for postpartum weakness and constipation.

　　3. Bananas

　　It can clear heat, moisten the intestines, and detoxify, suitable for people with hot constipation and habitual intestinal dry constipation. Eat raw bananas, 2 to 3 times a day, 2 bananas each time.

　　Treatment should be mainly conservative, and anal canal dilation under local anesthesia has significant effects. When conservative treatment is ineffective, surgical treatment can be considered.

　　1. Conservative Treatment:Oral coarse fiber food and the use of laxatives can achieve temporary effects, but cannot cure. Under local anesthesia, anal canal dilation has certain efficacy. Biofeedback therapy can train the body's control function and has good efficacy.

　　2. Surgical Treatment:For those who are ineffective with strict conservative treatment, IAS and partial resection of the rectal smooth muscle can be considered. Heaton reported that 53 patients with severe chronic constipation who were ineffective with long-term conservative treatment underwent this surgery, and 48 cases were followed up postoperatively, 26 cases showed good effects, 8 cases showed significant improvement, and 14 cases showed poor effects. Shafik reported that 146 patients with primary hyporectum underwent IAS ligation surgery, and postoperatively, 132 cases (90.4%) showed improved symptoms, defecation frequency and rectal pressure also returned to normal, and there was no recurrence during the follow-up period of 3 to 7 years. Therefore, IAS ligation surgery is a valuable method for treating spastic contraction of the anal canal sphincter.