Constipation is a causative, or aggravating, factor of GERD, and we should pay attention to the etiology of constipation and treat it promptly.
A. Constipation can be divided into two categories: organic and functional, in terms of etiology.
1, organic etiology mainly includes.
(1) intestinal organism: 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 canal.
(7) Neuromuscular lesions of the colon: pseudo-intestinal obstruction, congenital megacolon, megarectum, etc.
(8) Neuropsychological disorders.
(9) Pharmacologic factors: iron, opioids, antidepressants, antiparkinsonian drugs, calcium channel antagonists, diuretics, and antihistamines.
If constipation does not have a clear cause such as the above, it is called functional constipation. In the population with a history of constipation, functional constipation accounts for about 50%.
2, functional etiology: the cause of functional constipation is not clear, its occurrence is related to a variety of factors, including.
(1) eating less or food lack of fiber or water, the stimulation of the colon 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 and frailty, too little activity, intestinal spasm resulting in defecation difficulties, or due to the length of the colon.
Second, constipation according to the pathogenesis is divided into two main categories: slow transmission type constipation and exit obstruction type constipation.
1, slow transmission type constipation
It 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 hemicolectomy. It is most common in young women and occurs around puberty, characterized by reduced frequency of bowel movement (less than 1 bowel movement per week), less bowel movement, hard stool, and thus difficult to defecate; no stool or hard stool is palpated during anorectal examination, while the contraction and forceful defecation function of the external anal sphincter is normal; prolonged total gastrointestinal or colonic transmission time; lack of evidence of outlet obstruction type, such as balloon expulsion test and anorectal manometry Normal. Non-surgical treatment methods such as increased dietary fiber intake with osmotic laxatives are ineffective. Diabetes, scleroderma combined constipation and drug-induced constipation are mostly slow transmission type.
2, exit obstruction type constipation
It is due to muscle incoordination in the abdomen, anorectum and pelvic floor that leads to fecal discharge obstruction. It is especially common in elderly patients, many of whom are ineffective with 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.
In the diagnosis and differential diagnosis of constipation, the necessary tests should be performed according to clinical needs. First, attention should be paid to the presence of alarm symptoms and evidence of the presence of other systemic organic pathologies.
Colonoscopy should be performed in patients over 50 years of age with a history of chronic constipation and worsening symptoms in a short period of time 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 in the diagnosis of congenital megacolon.
Special tests include: gastrointestinal passage test, rectal and anal manometry, recto-anal reflex test, tolerance sensitivity test, balloon expulsion test, pelvic floor electromyography, pubic nerve latency determination test and anal canal ultrasonography, which are chosen only in cases of refractory constipation.
The following tests are commonly used for refractory constipation.
1, stool routine and occult blood, should be routine examination.
2. Tests related to biochemical and metabolic aspects. If the clinical manifestations suggest that the symptoms are due to inflammation, tumor or other systemic diseases, then hemoglobin, hematocrit, relevant biochemical tests (e.g. thyroid function, calcium, blood glucose and other relevant tests) should be performed.
3.Anorectal finger examination, which can understand the presence of masses and the function of the anal sphincter.
4.Colonoscopy or barium enema helps to determine the presence of organic causes. Especially when there is a recent change in stool habit, blood in stool or other alarm symptoms (such as weight loss, fever), whole colon examination is recommended to clarify the presence of organic lesions such as colon cancer, inflammatory bowel disease, colon stricture, etc.
5.Gastrointestinal transmission test: It is helpful to determine whether there is slow transmission, and is often taken at 48h and 72h.
6.Fecal imaging can dynamically observe anatomical and functional changes of anorectum. Defecography can assess the speed and completeness of rectal emptying, the degree of anorectal angle and perineal descent. In addition, fecal imaging can detect organic lesions such as huge rectal protrusion, rectal mucosal prolapse or overlap.
7.Anorectal manometry can check whether the anorectal function is impaired.
8.24h colonic pressure monitoring has some significance in guiding whether to operate or not. If there is a lack of specific propulsive contraction wave (SPPW) and a lack of response of the colon to waking up and eating, it indicates colonic weakness and can be considered for surgical resection.
9.Anal manometry combined with ultrasound endoscopy can show whether there is a mechanical deficiency and anatomical deficiency of the anal sphincter, which can provide clues for surgery.
10.Application of perineal nerve latency or electromyography can distinguish whether the constipation is myogenic or neurogenic.
11.Other Patients with significant anxiety and depression should be investigated and the causal relationship with constipation should be determined.