Rectal prolapse

Introduction to rectal prolapse Rectal prolapse refers to a pathological state in which the anal canal, the rectum or even the lower end of the sigmoid colon is displaced downward beyond the anus. Only the submucosal dislocation is incomplete prolapse, the full rectal prolapse of the rectum is completely prolapsed, the prolapsed part is located in the rectum and the internal prolapse is called, and the prolapse is called the external prolapse. The main symptom is the swelling of the mass from the anus. The tumor is small at the initial onset, and it is released when the bowel movement occurs, and then resets itself. After the tumor is removed from the gradual frequency, the volume is increased, and then the back of the anus should be carried by hand, accompanied by incomplete defecation and falling feeling. Finally, you can also get rid of coughing, exerting force and even standing. Rectal prolapse is more common in children and the elderly. Rectal prolapse is a self-limiting disease in children. Most of them are self-healing before the age of 5, so non-surgical treatment is the main cause, and adults with complete rectal prolapse are more serious. Long-term prolapse will cause anal incontinence, ulceration, perianal infection, rectal bleeding, edema, necrosis and stenosis of the intestine, which should be treated mainly by surgery. basic knowledge The proportion of illness: 0.002% - 0.004% Susceptible people: good for the elderly, children Mode of infection: non-infectious Complications: ulcer bleeding, anal incontinence, intussusception

Cause of rectal prolapse

Anatomical factors (30%):

In children, the curvature of the appendix is small, the rectum is vertical, the intra-abdominal pressure is increased, the rectum lacks support and is prone to prolapse. The rectum is concave and the peritoneal reflex is too low. The intra-abdominal pressure and intestinal pressure force the rectal anterior wall to protrude into the rectum. Cause prolapse, muscle relaxation in the elderly, excessive birth or perineal tear during childbirth can also cause prolapse of the rectum.

Increased intra-abdominal pressure (20%):

Long-term constipation, diarrhea, chronic cough and dysuria cause increased intra-abdominal pressure, which can lead to rectal prolapse. In recent years, foreign studies have found that rectal prolapse is often accompanied by mental or neurological disorders. The relationship between the two is still unclear. Some people think that when the nervous system is diseased, the function of controlling and regulating the bowel movement is disordered. The rectum is chronically dilated, and the sensitivity to fecal stimulation is weakened, resulting in constipation and decreased ability to control bowel movement. Abnormal exertion during defecation, so that the levator ani muscle and pelvic floor Tissue function is weakened and is a common cause of rectal prolapse.

Other trauma (10%):

Surgery causes lumbosacral nerve palsy, causing relaxation of the anal sphincter, causing rectal mucosal prolapse.

Pathogenesis

Pathophysiology

(1) Factors that maintain rectal stability: Mass and Rives pointed out that the stability of the rectum is a complex mechanism, and the basic factors for stabilizing the rectum are 3 .

1 Active support: This is the most important part of maintaining the stability of the rectum. This support comes from the rectal stabilizing dynamic mechanism provided by the levator ani muscle. Pecamore describes the anatomy and function of the pelvic levator ani muscle in detail. The anus muscle starts from the anterior and lateral wall of the pelvis and ends at the pelvic organ and the lower end of the spine, but has a triangular split in the front of the midline. The edge of the triangle is turned back and consists of the medial edge of the levator ani muscle. The muscle bundle of the margin is very thick, the posterior part of which is connected behind the rectum, and the front part is suspended on the pubic arch. The rectum and the muscle sling have extremely strong adhesion, due to the rectal longitudinal muscle and the levator ani muscle. It has a wide range of interlacing, and this interlacing along the rectal longitudinal muscles has a considerable area, thus providing a strong attachment and fixation to the pelvic floor. The levator ani muscle plays an important supporting role in maintaining the stability of the rectum. Muscle, the rectum will come out when defecation, because it constitutes the medial edge of the pelvic floor, and the muscle bundle in which the suspension acts is the puborectalis muscle, which acts to lower the rectum. Lifting forward and upwards, causing an acute angle to the anorectal rectum and pressing it on the frontal tissue structure, thereby narrowing the rupture of the pelvic floor. This effect is not only strong and strong support for the rectum, but also all organs of the pelvic cavity. They all constitute a more complete and powerful bottom. When the muscle bundle sling relaxes, the pelvic floor descends, the acute rectal angle disappears, the rectum straightens, and the rectal cavity moves more directly to the pelvic floor sulcus. In short, the levator ani muscle In particular, the puborectalis muscle constantly adjusts and changes its tension according to the pressure changes it receives from above to maintain its support for stable rectum.

2 Passive support: This is supported by various connective tissues around the rectum, including peritoneal reflexes, mesenteric and pelvic fascia attached to the bone, vagina or prostate. Some people think this is the main factor for stabilizing the rectum, however This is a misunderstanding. Experimental studies have shown that when long-term continuous exertion, connective tissue can be elongated and relaxed. The best clinical example is pregnancy in women. Due to increased long-term abdominal pressure, the abdominal white line is elongated, and the postpartum abdomen Stretch marks can occur, especially in prolific women. It is undeniable that these connective tissues around the rectum do play the role of pulling the rectum to prevent prolapse when relaxing at the pelvic floor. However, rectal prolapse is not as common as stretch marks. Commonly, it indicates that connective tissue is pulled under the same increase of abdominal pressure, and relaxation does not lead to rectal prolapse. Then, the connective tissue to the rectum is fixed and the supporting effect becomes a secondary status.

3 Robustness and position: This refers to the stabilizing effect of the normal human spine and pelvis on the rectum. The inclination of the pelvis and the curvature of the spine advance the gravity of the abdominal viscera, leaving the pelvic floor and causing the rectum to bend and walk through the pelvis. This disperses the stress in multiple directions, thereby reducing its direct effect on the pelvic floor.

(2) Changes in defecation function and control ability: When the sensory center of the cerebral cortex is stimulated by changes in the pressure in the rectum, after the indication of defecation is issued, the contraction of the anterior abdominal wall and the diaphragm is started. This is an action to increase the abdominal pressure. At the same time, the levator ani muscle is inhibited, the puborectalis muscle is relaxed, the pubic rectal sling is prolonged, the pelvic floor is lowered, the anorectal angle is disappeared, and the external anal sphincter is functionally relaxed with the levator ani muscle as a whole, so that the rectum is relatively compared. In the vertical position, the feces in the intestine are expelled from the pressure from the upper surface, including the abdominal cavity and the intestine, and the contraction of the rectum's own ring muscle. During the defecation process, the rectum is always subjected to the levator ani muscle attached to the bottom. Mainly the support of the pubic rectum, and various ligament tissues to fix it on the adjacent structure. At this time, the tension of these ligament tissues is obviously increased. After the defecation, the puborectalis muscle contraction, and the levator sling is restored to the original The support site simultaneously relieves tension on all surrounding ligament tissue.

The normal person's ability to maintain sound control depends on the complete sphincter function, the sharp sensory reflex and the good fecal function. The ability to control the rectal prolapse is obviously weakened or even lost. The mechanism is not completely clear. However, it seems that it is a long-term, repeated prolapse caused by the consequences, because the patient has many obstacles in the early control of the ability, recent research found that the nerves that control the small rectal muscles are histologically abnormal, Parks et al believe that this is Pulling the perineal and pudendal nerves, but in the event of defecation incontinence, surgery can not improve the function of defecation control. Therefore, it is important to perform surgery before prolapse and incontinence. Special attention should be paid to the incontinence of some patients before surgery. Incontinence is caused by postoperative incontinence. The reason is that the prolapsed intestine segment masks the incontinence. The incontinence is obvious after the prolapse is resolved. Therefore, patients with severe prolapse and long history should be vigilant even if they have no incontinence before surgery. Patients and their families explain the possibility of postoperative incontinence, so as to avoid unnecessary misunderstanding. In theory, anal tension is negatively correlated with defecation incontinence, but clinically Non-radically, it can not be judged solely anal tension, in particular, should not be thought of anal tension can still be delayed timing of surgery.

2. Pathogenesis

There are currently four theories about the pathogenesis of rectal prolapse.

(1) Slippery theory: patients with rectal prolapse have a common, constant anatomical feature, that is, the rectum sag is abnormally low and deep. Moschointg described this phenomenon as early as 1912, and considered this to be prolapsed in the rectum. The etiology is of great significance. It is suggested that rectal prolapse is a kind of slippery, rectal anterior depression (cul-de-sac) peritoneal reflex is too low, rectal bladder or rectal uterus is too deep, forming a hernia sac, when abdominal pressure When the height is increased, the anterior wall of the rectum is compressed, and the contents of the abdominal cavity push the anterior wall of the rectum into the rectal cavity and out through the anal canal. The evidence supporting this theory is that when the clinical examination is performed, the patient is kneeling and the rectum is prolapsed. It can be seen that the rectal cavity is not in the center, indicating that the anterior rectal wall is more prolapsed than the posterior wall. When the finger is inserted into the intestine, the thumb and finger are used to gently pinch the intestine wall. There are more tissues, including descending rectal peritoneal reflexes, small intestines and prolapsed intestines, not just two layers of intestinal wall, which is currently considered to be the most important pathogenesis leading to rectal prolapse.

(2) Perineal descending syndrome theory: In 1966 Parks proposed that the rectal wall of the rectum usually covers the upper part of the anal canal more tightly when the abdominal wall contracts, but does not protrude into it, that is, the flap valve self-made theory, if For some reason, rectal emptying is not normal, then resort to further abdominal wall force, resulting in pelvic floor muscle elasticity decline or even disappear, the entire pelvic floor decline due to the puborectal muscle and sphincter upper part is elongated to become funnel-shaped, in the lower rectum The feces are pressed against the funnel-shaped anorectal area, but the force that discharges the feces is the peristalsis of the colon. The fecal mass is pushed down, the front wall of the rectum is pushed open to open the flap, and the feces fall into the anal canal to form a strong feeling of defecation. The abdomen exerts force to push the feces into the anal canal through the anterior wall of the rectum, thereby accelerating the discharge of the feces. After the normal emptying of the rectum, there is a contraction of the pelvic floor muscles to retract the anterior wall of the lower rectum, covering the anal canal, and the flap is restored. Close the anal canal, this is the reduction and reflex after the stool, and restore the rectal angle of the anus. If the abdominal wall is forced to defecate for more than a few years, the pelvic floor reflex effect after the stool When the rectal anterior wall mucosa falls into the anal canal, it is not easy to reset, and the nerve endings of the tooth line are stimulated to cause a feeling of bulging, which makes the patient more forceful to defecate, forming a vicious circle, and finally the perineum continues to decline to form drscending perineum syndrome. If it continues to develop, it will cause nesting or prolapse.

However, it is also believed that the flap has little effect on maintaining self-control. When the intra-abdominal pressure rises, the reflex pressure of the sphincter rises, forming a pressure barrier to maintain self-control, but agreeing that the flap, ie the rectal anterior wall above the upper anal canal, can occur in the rectum. Prolapse of the anterior wall leads to obstructive defecation.

In 1985, Swash proposed that childbirth can cause pudendal nerve damage to the pelvic floor striated muscle. The related risk factors are excessive or excessive fetal weight during labor, prolonged second stage of labor, application of forceps, especially multiple births, most primipara injuries. Can be quickly restored, and multiple births can not be recovered due to repeated injuries, resulting in difficulty in defecation to forced defecation, repeated perineal lowering pulls the pudendal nerve to form a vicious circle, resulting in rectal intussusception, namely: vaginal delivery sphincter nerve Degeneration perineal decline intractable defecation force rectal intussusception.

Johansson and Berman also agree that perineal descent syndrome and rectal prolapse are the same disease, suggesting that the following processes may exist: obesity, advanced age, childbirth, anal surgery or post-inflammatory stenosis, etc. excessive force defecation mucosal prolapse rectal solitary ulcer Syndrome and perineal decline syndrome rectal intussusception.

(3) Intussusception theory: Devadhar proposed in 1967 that the first is the rectal mucosal sensation decline, causing rectal dilatation, massive fecal impaction, reflex caused strong contraction of the rectal muscle system, emphasizing the existence of "key points" - the largest The feeling of weakening and causing excessive contraction of the muscles is in a constant and predictable position, generally 5 cm below the humerus, and the excessive contractile force of the rectal muscle system is concentrated for a long time, so that the anterior rectal wall is concave into the rectal cavity, gradually A nested change is produced which eventually forms prolapse.

In 1968, Broden and Snellman Devadhar and Theuarkauf injected contrast agents through the rectum, sigmoid colon, Douglas fossa, vagina and bladder cavity respectively. The visceral movements of rectal prolapse were observed by radiographic camera technique. It was found that the rectal prosthesis was first started. The starting point of the stack, the nesting is often 6-8 cm from the anal margin, and the affected intestine is not simply the anterior rectal wall, but the entire rectum is folded down the intestine wall, and when the tip is lowered to the lower end of the rectum , that is, the anus is removed outward, and when the prolapsed part is completely lowered, the rectal peritoneal reflex can be included - the Douglas fossa and the small intestine are prolapsed through the anus, but in the early stage of prolapse or collapse, even if it has come out of the anus, There can be no small intestine, as to why it causes rectal intussusception, there is no exact explanation yet.

Devadhar pointed out that when the rectal prolapse, the rectal anterior wall is not more than the posterior wall, and the intestine is not behind, still centered, but when the maximum force is applied downward, the front part of the intestine often pulls out more, and the intestine is also Not in the center, only a few of the patients with rectal prolapse belong to this type.

(4) The theory of levator dysfunction syndrome: In 1981, Shafik proposed that due to long-term exertion of defecation, neuropathy or systemic failure caused levator sag, rectal caudal suture, fissure ligament and levator detachment and separation. The widening and lowering of the muscle fissure causes the rectal neck to be under the direct action of the intra-abdominal pressure, causing all the visceral organs to lose the support of the levator muscle and its ligament and relax. At this time, if the defecation is forced, the levator muscle contraction before the descending feces The rectal neck can be opened, and the increased intra-abdominal pressure is transmitted through the wide levator fissure, further closing the rectal neck, causing intussusception and prolapse.

Butler, Muir, and Todd also point out that most patients with rectal prolapse have muscle weakness in the anal sphincter, including the levator ani muscle, even in early cases, and in the case of cauda equina patients, pelvic floor muscles are shown. And anal sphincter relaxation, but there is no clinical evidence that the anal sphincter and pelvic floor muscle relaxation are caused by neurological diseases. Porter reported that these muscles in rectal prolapse and normal people can be seen in the EMG measurement. The difference between the normal human rectum and the balloon expansion can reflect the static activity of the external sphincter and the levator ani muscle, just like before defecation and during defecation. In the case of rectal prolapse, this reflex inhibition is significantly prolonged. It is highly probable that this sphincter function disorder is the primary pathogenesis factor, while muscle relaxation, deep rectal recession and rectal activity are secondary factors. In fact, patients with rectal prolapse can have a normal pelvic floor. And the sphincter function, Goligher saw 3 cases of rectal prolapse and return, the anal sphincter and levator ani muscles were completely normal, Broden and Snellman saw the rectum from photography The initial rectal intussusception, starting above the pelvic floor, indicates that the pelvic floor muscle relaxation is not the primary factor. Fry, Griffiths and Smart have once again confirmed from the photography of these muscles that the initial cause of rectal prolapse is not the pelvic floor. Weak, 12 cases of pelvic floor activity were normal in 15 cases of rectal prolapse.

Rectal prolapse prevention

Patients with rectal prolapse should insist on physical exercise and strong abdominal muscle exercise to improve the body's qi and blood deficiency and lack of gas. This has important practical significance for consolidating the curative effect and preventing rectal prolapse. The specific preventive measures are:

1. Actively remove various predisposing factors, such as cough, sedentary standing, diarrhea, long-term cough, enteritis and other diseases, especially for infants and young children.

2. Usually pay attention to increase nutrition, regular life, do not sit on the potty for a long time, develop the habit of regular bowel movements, prevent dry stools, and then use hot water to sit in the bath and stimulate the contraction of the anal sphincter. It has a positive effect on preventing rectal prolapse.

3. Patients with habitual constipation or difficulty in defecation, in addition to eating more food containing cellulose, do not use excessive force during defecation.

4. Women should take adequate rest during childbirth and postpartum to protect the normal function of the anal sphincter. If there is uterine ptosis and visceral ptosis, it should be treated promptly.

5. Regular anal gymnastics, promote the movement of the levator ani muscles, and enhance the function of the anal sphincter, which has a certain effect on the prevention of this disease.

Rectal prolapse complications Complications ulcer disease massive bleeding anal incontinence intussusception

1. Bleeding: Occasionally, massive bleeding can occur due to sore ulceration of the rectum.

2. Anal incontinence: 16% to 20% of gas incontinence, 17% to 24% of total incontinence, causes of incontinence caused by rectal prolapse include:

1 rectal prolapse produces substantial rectal dilatation, causing sustained reflex inhibition and relaxation of the anal sphincter, especially in the elderly due to weak puborectal muscle, when the flap does not play a major role, once the internal sphincter dysfunction, it will cause incontinence .

2 childbirth or long-term forced defecation to abnormally reduce the perineum, causing the genital nerve to be stretched and stretched, making the pelvic floor striated muscle denervation weak, anorectal manometry to help understand the function of the anal sphincter, Zhang Lianyang and other rectum The results of anal canal pressure measurement in patients with internal prolapse showed that there was a decrease in anal canal pressure, in which rectal mucosal prolapse had a decrease in resting pressure of the anal canal, while full-thickness rectal intussusation had anal canal resting pressure and cough pressure. reduce.

Rectal Prolapse Symptoms Common Symptoms After anxious, heavy anal bulge, weakness, bloody constipation

Rectal prolapse can occur at any age and is more common in children and the elderly.

Clinical classification

According to the degree of prolapse, it is divided into two types: partial prolapse and complete prolapse.

(1) Partial prolapse: the lower mucosa of the rectum is separated from the muscular layer and displaced downward to form a fold. Therefore, it is also called mucosal prolapse or incomplete prolapse. The prolapsed tissue is less, and the length is 2 to 5 cm. It is a partial mucosa or a full-circle mucosa, which can be arranged in a radial arrangement. The prolapsed part is a two-layer mucosa with no groove between the anus and the anus.

(2) Complete prolapse: for the full rectal prolapse, in severe cases, the rectum and anal canal are turned out of the anus, and there are many tissues, the length is often more than 10cm, the shape is pagoda-like, the mucosal folds are arranged in a ring shape, and the prolapsed part For the two-layer folded intestinal wall tissue, most adults are completely prolapsed, more women, often accompanied by anal dysfunction.

2. Symptoms and signs

Patients with rectal prolapse often have chronic constipation, irregular history of defecation, slow onset, early feeling of rectal fullness, and unreported feces. Later, when there is a defecation, there is a mass that is prolapsed and then retracted by itself, and the disease is coughing later. Or walking out will take off, you need to hold the anus by hand, such as the rectum is not timely back after the prolapse, can occur swelling, inflammation, and even twisted necrosis, the patient often feels that the stool is not exhausted, the mucus flows out of the anus, blood in the stool, anus Swelling, pain and urgency, sometimes accompanied by waist, lower abdomen or perineal soreness.

There was no abnormality in the abdominal examination, and the paralyzed patient performed the squatting movement, and the rectum was removed.

Diagnosis of rectal prolapse is not difficult. The patient underwent forced defecation action. You can see the red spherical mass protruding from the anus 2 to 5 cm. There are radial grooves, which are indicated as two layers of folded mucosa, which are retracted after defecation. The fully prolapsed prolapsed intestine segment is long, elliptical or pagoda-like, about 10cm long, with a layer of folded annular folds, the muscle layer can be touched between the two layers of mucosa, and the rectal finger can sense the anal sphincter relaxation. Confirmed diagnosis.

Rectal prolapse examination

1. Anal visual examination: It can be found that there is a soft mass of intestinal mucosa prolapsed outside the anus when defecation, and the intestinal mucosa is removed from the anus when the patient defecates.

2. Digital rectal examination.

3. Blood and urine will be routinely examined.

4. Rectal examination.

5. Barium enema: to understand whether there is too long sigmoid colon.

6. Defecation angiography: visible in the force line first appeared in the rectum, and then developed into rectal prolapse.

Diagnosis of rectal prolapse

diagnosis

According to the medical history, clinical manifestations and laboratory data is not difficult to make a diagnosis.

Differential diagnosis

Rectal mucosal prolapse needs to be differentiated from the annular internal hemorrhoids. The history of the two is different. The ring-shaped internal hemorrhoids can be seen as plum-shaped sputum, the congestion is dark red, easy to hemorrhage, the sac is the normal mucosa of the depression, rectal examination, sphincter contraction Potent, and rectal mucosal prolapse has sphincter relaxation.

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