Constipation is a common and complex clinical symptom rather than a disease. It mainly refers to a decrease in the number of bowel movements, a decrease in the volume of stool, dry stool and straining to defecate. It must be combined with the nature of the stool, the usual bowel habits and the difficulty of defecation to make a judgment of constipation. If it is more than 6 months, it is chronic constipation.
I. Etiology
Constipation can be divided into two categories from the etiology: organic and functional.
1.Organic
(1) organic lesions of the intestinal canal tumor, inflammation or other causes of intestinal lumen narrowing or obstruction.
(2) Rectal and anal lesions Endorectal prolapse, hemorrhoids, prerectal bulge, puborectal hypertrophy, puborectal separation, pelvic floor disease, etc.
(3) Endocrine or metabolic diseases Diabetes mellitus, hypothyroidism, parathyroid disease, etc.
(4) Systemic diseases Scleroderma, lupus erythematosus, etc.
(5) Neurological disorders Central brain disorders, stroke, multiple sclerosis, spinal cord injury, and peripheral neuropathy, etc.
(6) Smooth muscle or neurogenic lesions of the intestinal tract.
(7) Colonic neuromuscular pathology Pseudo-intestinal obstruction, congenital megacolon, megarectum, etc.
(8) Neuropsychological disorders.
(9) Pharmacological factors Iron, opioids, antidepressants, anti-Parkinson’s disease drugs, calcium channel antagonists, diuretics and antihistamines, etc.
2.Functional
The cause of functional constipation is not clear, and its occurrence is related to a variety of factors, including.
(1) eating less or food lack of fiber or water, the stimulation of colonic movement is reduced.
(2) Normal bowel habits are disturbed by work stress, fast-paced life, changes in the nature and timing of work, and mental factors.
(3) Due to colonic motility disorder, commonly caused by irritable bowel syndrome, caused by spasm of colon and sigmoid colon, with abdominal pain or bloating in addition to constipation, and some patients may exhibit alternating constipation and diarrhea.
(4) Insufficient tone of the abdominal and pelvic muscles, insufficient pushing force for defecation, and difficulty in expelling feces from the body.
(5) Abuse of laxatives, forming drug dependence, resulting in constipation.
(6) Old age, weakness, low activity, intestinal spasm, resulting in difficulty in defecation, or due to the length of the colon.
3.Classification
Constipation is divided into two main categories according to the pathogenesis: slow transmission type and outlet obstruction type.
(1) Slow-transit constipation is caused by the weakened contractile movement of the intestine, which slows down the movement of feces from the cecum to the rectum, or by the uncoordinated movement of the left hemicocele. It is most common in young women and occurs around puberty. It is characterized by reduced frequency of bowel movements (less than 1 bowel movement per week), less bowel movements, hard stools, and thus difficult defecation; no stools or hard stools are palpated on anorectal examination, while the contraction of the external anal sphincter and forceful defecation function are normal; prolonged total gastrointestinal or colonic transmission time; lack of evidence of outlet obstruction type, such as balloon expulsion test and anorectal manometry Normal. Increased dietary fiber intake with osmotic laxatives is ineffective. Constipation in combination with diabetes, scleroderma and drug-induced constipation are mostly of the slow-transmission type.
(2) Exit-obstruction constipation is due to muscle incoordination in the abdomen, anorectum, and pelvic floor, resulting in fecal impaction. It is particularly common in elderly patients, many of whom have failed to respond to conventional medical treatment. The outlet obstruction type may have the following manifestations: straining to pass stool, a feeling of incompleteness or falling, a small amount of stool, a desire to pass stool or a lack of desire to pass stool; a lot of muddy stool in the rectum on anorectal examination, the external anal sphincter may contract paradoxically during straining to pass stool; the whole gastrointestinal or colonic transit time shows normal, most markers may be retained in the rectum; anorectal manometry shows that the external anal sphincter contracts paradoxically during straining to pass stool contraction or abnormal sensory threshold of the rectal wall, etc. Many patients with outlet obstruction constipation also have a combination of slow transmission constipation.
Clinical manifestations
Constipation has a prevalence of up to 27% in the population, but only a small percentage of constipated individuals will be seen. Constipation can affect people of all ages. It is more common in women than in men, and in the elderly than in the young and old. Because of the high prevalence and complex causes of constipation, patients often suffer a lot of distress, and constipation can affect the quality of life when it is severe.
Constipation is often manifested as: less bowel movements, less frequent bowel movements; difficult and laborious bowel movements; poor bowel movements; dry and hard stools, unclean bowel movements; constipation accompanied by abdominal pain or abdominal discomfort. Some patients also have insomnia, irritability, dreaminess, depression, anxiety and other psychiatric disorders.
Because constipation is a more common symptom, symptoms vary in severity, most people often do not pay special attention to constipation is not a disease, no treatment, but in fact, constipation is very harmful. The “alarm” signs of constipation include blood in stool, anemia, weight loss, fever, black stool, abdominal pain, and family history of tumor. If there are alarm signs, you should go to the hospital immediately for further examination.
III. Examination
In the diagnosis and differential diagnosis of constipation, the necessary tests should be done according to clinical needs. First of all, attention should be paid to the presence of alarm symptoms and evidence of other organic lesions in the body; for patients over 50 years old with a history of long-term constipation and worsening symptoms in a short period of time, colonoscopy should be performed to exclude the possibility of colorectal tumors; for long-term laxative abuse, colonoscopy can determine the presence of laxative colon or (and) colonic melanosis; barium enema angiography can help the diagnosis of congenital megacolon.
Special tests available for refractory constipation include: gastrointestinal passage test (GITT), rectal and anal manometry (RM), recto-anal reflex test, tolerance sensitivity test, balloon expulsion test (BET), pelvic floor electromyography, pubic nerve latency measurement test and anal canal ultrasonography; colonoscopy or barium enema helps to determine the presence of organic lesions.
IV. Diagnosis
Ask patients about their diet, living habits and work, past history of disease and surgery, especially the history of hemorrhoids, anal fistula and anal fissure, recent history of medication, especially the history of long-term laxative use, and clarify the causes of constipation as much as possible through the corresponding examination. For middle-aged patients or above, if there is a change in stool habit from once a day or once every 2 days to once every 3 days or several days, they should be alerted to the possibility of left hemicolectomy.
V. Treatment
1.General treatment
Patients with constipation need to adopt comprehensive treatment according to the severity, cause and type of constipation, including general life treatment, drug treatment, biofeedback training and surgical treatment, in order to restore normal defecation physiology. Emphasis should be placed on lifestyle treatment, strengthening patient education, adopting reasonable dietary habits, such as increasing dietary fiber content, increasing water intake to enhance stimulation of the colon, and developing good defecation habits, such as morning bowel movements, timely defecation when there is an urge to defecate, avoiding straining to defecate, and at the same time, activities should be increased. During treatment, attention should be paid to the removal of excessive accumulation of feces in the distal rectum; positive attitude adjustment is needed, which is extremely important to obtain effective treatment.
2.Drug treatment
(1) Volumetric laxatives mainly include soluble fiber (pectin, plantain, oat bran, etc.) and insoluble fiber (plant fiber, lignin, etc.). Volumetric laxatives have a slow onset of action with few side effects and are safe, so they are more effective for constipation in pregnancy or mild constipation, but are not suitable for rapid laxative treatment of temporary constipation.
(2) lubricating laxatives can lubricate the intestinal wall, soften the stool, so that the stool is easy to discharge, easy to use, such as cork, mineral oil or liquid paraffin.
(3) salt laxatives such as magnesium sulfate, magnesium milk, these drugs can cause serious adverse reactions, clinical caution should be used.
(4) osmotic laxatives commonly used drugs are lactulose, sorbitol, polyethylene glycol 4000, etc.. Suitable for blocked feces or as a temporary treatment measure for chronic constipation, is a better choice for constipation patients with poor efficacy of volumetric light laxatives.
(5) Stimulant laxatives include anthraquinone-containing botanical laxatives (rhubarb, Frangipani, senna, aloe), phenolphthalein, castor oil, diethylstilbestrol, etc. Stimulant laxatives should be used only when volumetric laxatives and salt laxatives are ineffective, some of them are stronger and not suitable for long-term use. Long-term application of anthraquinone laxatives can cause colonic black stool disease or laxative colonization, causing atrophy of smooth muscle and damage to the inter-intestinal muscular plexus, but aggravate constipation, reversible after discontinuation of the drug.
(6) prokinetic agents Mosapride, Itopride has a pro-gastrointestinal dynamics, Proscapride can selectively act on the colon, can be selected according to the situation.
3.Device aid
If the stool is hard and stagnant in the rectum near the anal opening or if the patient is old and frail and has poor defecation power or lack of it, colon hydrotherapy or cleansing enema can be used.
4.Biofeedback therapy
It can be used for constipation patients with recto-anal and pelvic floor muscle dysfunction, and its long-term efficacy is better. Biofeedback therapy can train patients to relax the pelvic floor muscles during defecation, so that the abdominal muscles and pelvic floor muscle groups can coordinate their activities during defecation; and for patients with abnormal threshold of bowel movement, emphasis should be placed on the reconstruction of the defecation reflex and the training to adjust the perception of bowel movement. There are no specific norms for the training program, and the training is more intense but safe and effective. For patients with pelvic floor dysfunction, biofeedback therapy should be preferred over surgery.
5.Cognitive therapy
Patients with severe constipation often have anxiety or even depression and other psychological factors or disorders, and should be given cognitive therapy to eliminate the patient’s tension, and if necessary, give antidepressant and anti-anxiety treatment, and ask psychologists to assist in the diagnosis and treatment.
6.Surgical treatment
For severe intractable constipation all the above treatments are ineffective, if the colon transmission dysfunction type constipation, serious condition can be considered for surgery, but the long-term effect of surgery is still controversial, case selection must be careful. In this huge group of constipation, those who really need surgical treatment are still in a very small minority.
Six, prevention
1, avoid eating too little or too fine food, lack of residues, and reduced stimulation of colonic motility.
2, avoid disturbance of defecation habits: failure to defecate in a timely manner due to mental factors, changes in lifestyle patterns, long-distance travel overexertion, etc. can easily cause constipation.
3, avoid the abuse of laxatives: the abuse of laxatives will make the intestinal sensitivity is weakened, the formation of dependence on certain laxatives, resulting in constipation.
4, reasonable arrangement of life and work, to achieve a combination of work and rest. Appropriate physical and cultural activities, especially the exercise of the abdominal muscle is conducive to the improvement of gastrointestinal function, more important for sedentary and less active and highly concentrated brain workers.
5, to develop good bowel habits, regular daily defecation, forming a conditioned reflex, to establish a good bowel pattern. Do not ignore when you have the intention to defecate, defecate in a timely manner. The environment and posture of defecation should be as convenient as possible, so as not to inhibit the desire to defecate and destroy the defecation habit.
6. Patients are advised to drink at least 6 glasses of 250 ml of water daily, perform moderate exercise and develop the habit of regular bowel movements (2 times a day for 15 minutes each time). The action potential activity of the colon is enhanced after waking up and after meals, which pushes the stool toward the distal end of the colon, so morning and after meals are the easiest time to defecate.
7, timely treatment of anal fissures, perianal infections, uterine adnexitis and other diseases, laxatives should be applied with caution, do not use strong stimulation methods such as bowel cleansing.