OVERVIEW
Functional anorectal disease is a clinical syndrome based on anorectal symptoms without evidence of structural abnormalities, systemic or neurologic disease. The main clinical manifestations include constipation, anal incontinence, anorectal pain, etc. Psychological symptoms such as depression and anxiety may also be present.
Classification
1. Functional anal incontinence.
2. Functional defecation disorders: ① uncoordinated defecation; ② defecation propulsion insufficiency.
3. Functional anorectal pain: ① chronic anorectal pain: anorectal muscle syndrome, non-specific functional anorectal pain; ② spasmodic anorectal pain.
Etiology
The etiology is not clear, may be related to the following factors.
1. Functional anal incontinence may originate from abnormal coordinated movement of the external anal sphincter, puborectal muscle weakness, reduced rectal compliance, rectal sensorimotor dysfunction, and reduced resting voltage of the internal anal sphincter.
2. Functional defecation disorder may be acquired behavioral disorder.
3. Functional anorectal pain is associated with spasm or over-contraction of the pelvic floor muscles, mental stress, anxiety and tension.
Symptoms
1. Digestive system symptoms
(1) Constipation: mainly seen in patients with functional defecation disorder, mainly manifested as straining to defecate, time-consuming defecation, feeling of incomplete defecation, which may be accompanied by pain in the anorectal area.
(2) Anal incontinence: mostly occurs during the day, relatively rare at night, the fecal character can be simple liquid, gas-liquid mixture or solid.
(3) Pain: manifested as vague dull pain in the anorectal area, usually the pain lasts for a long time, with the pattern of mild symptoms in the morning, aggravated at noon and disappeared at night.
2. Other symptoms
There may be psychological abnormalities, such as anxiety, depression, obsessive-compulsive concepts and behaviors.
Examination
1. Physical examination
Anorectal examination may reveal that the anal sphincter is flaccid or has uncoordinated contractions.
2.Laboratory examination
(1) Blood routine: white blood cell count and neutrophil ratio are increased.
(2) Stool routine: attention should be paid to checking the fecal character, red and white blood cells, parasites (eggs), fat droplets, etc., in order to determine whether there is gastrointestinal bleeding, bacterial or parasitic infections and dyspepsia and other diseases.
(3) Blood gas analysis and water electrolyte examination: patients with prolonged diarrhea may have acid-base imbalance and water electrolyte disorders.
3. Imaging examination
(1) endoscopy: ① anal tube ultrasound endoscopy, which can detect sphincter thinning or defects; ② sigmoidoscopy or total colonoscopy to determine the presence of organic pathology; ③ by observing the mucosa of the digestive tract, to determine the presence of inflammatory lesions.
(2) Pelvic floor magnetic resonance: It can show the anatomy of the anal sphincter and overall pelvic floor movement in real time, and also observe the bladder and genitals.
(3) Defecography: It can evaluate bowel function and show the combined presence of rectal and pelvic floor morphological and structural abnormalities. Magnetic resonance fecography shows the soft tissue changes of the pelvic floor more clearly than conventional X-ray fecography.
(4) Electromyography: It can sensitively detect extraneous neuropathy and can often identify myogenic, neurogenic or mixed injuries.
4.Special examination
(1) Anal canal pressure measurement: the pressure measured when the patient is resting can reflect the function of the internal anal sphincter, the normal pressure is 80~140 mmHg, the pressure decreases in anal incontinence, and the external anal sphincter contraction can make the internal anal canal pressure increase.
(2) Balloon forcing out test: It is a screening test to evaluate the defecation function, but it cannot clarify the mechanism of defecation disorder.
Diagnosis
Digestive symptoms such as constipation, anal incontinence, and anorectal pain should be considered in the absence of a clear organic pathology. However, some patients’ recall of symptoms is not accurate, and laboratory tests and imaging tests are needed. Laboratory tests such as white blood cell count, neutrophil ratio and stool routine combined with endoscopy can exclude inflammation, and imaging tests can assess the condition of the rectum, anal sphincter, pelvic floor and neighboring organs; anal canal manometry is important for the diagnosis of functional incontinence, and the balloon forcing test is helpful in the diagnosis of functional defecation disorder. Balloon forcing test is helpful in the diagnosis of functional bowel incontinence.
Treatment
1. General treatment
(1) Adjustment of defecation habits: regular defecation habits can help to improve intestinal function.
(2) Dietary therapy: Increasing dietary fiber intake can enhance the absorption of water in the intestines and help control the symptoms of mild anal incontinence.
(3) Psychotherapy: Some of the patients’ accompanying neuropsychiatric symptoms are psychological in nature, and psychotherapy will be effective.
(4) Sitz bath: it can relax the anal sphincter and is effective for some patients.
2. Medication
According to different types of choice of drugs, functional anal incontinence choose loperamide hydrochloride capsules, phenethylpiperidine, montelukast and other antidiarrheal drugs; functional defecation disorders choose laxatives to improve the symptoms of constipation; functional anorectal pain can be chosen to relieve the pain of nifedipine, diltiazem, nitroglycerin ointment, salbutamol and so on. In addition, antidepressant or anti-anxiety drugs, such as selective 5-hydroxytryptophan, tricyclic drugs, etc. can be used as appropriate.
3. Biofeedback therapy
Through repeated positive and negative attempts of training, the coordination of pelvic floor muscles and the ability of diastolic perception can be improved. This treatment method is effective for some patients, and the success of biofeedback has a certain relationship with the patient’s willingness to accept the whole treatment process.
Prognosis
The prognosis is related to the patient’s physical condition, the availability of appropriate treatment measures and the timeliness of the measures taken.
Prevention
Hygiene education, good mood, good defecation habits, etc.
Nursing care
Long-term bedridden patients with anal incontinence should change their position, keep the perineum dry and clean, and prevent the perianal skin from being contaminated.