Overview of Functional Incontinence
Functional fecal incontinence refers to recurrent uncontrolled defecation without neuropathy or anatomical abnormality, also known as functional fecal incontinence, which is a kind of functional anorectal disease, and simple anal defecation cannot be regarded as this disease. The main clinical manifestation is recurrent uncontrollable defecation, which may be accompanied by fecal retention or involuntary defecation. Long-term illness will have certain psychological impact on the patients, and the quality of life may be affected in serious cases.
Causes
1. Pathogenesis
It is mainly due to the abnormal coordinated movement of external anal sphincter, weakness of puborectalis muscle, decreased rectal compliance, increased rectal sensory threshold and motor dysfunction, decreased resting pressure of internal anal sphincter, and increased frequency of spontaneous relaxation of anal canal.
2.Predisposing factors
Mobility, diarrhea and urgency to defecate, as well as obstetrical risk factors (e.g., forceps delivery, episiotomy, prolongation of the second stage of labor), a history of taking medications that induce or exacerbate fecal incontinence (e.g., laxatives, artificial stool softeners), and a history of anorectal surgery, can all induce functional fecal incontinence.
Symptoms
1. Typical clinical manifestations
The main manifestation is recurrent uncontrollable defecation, patients with urgent type have strong intention to defecate before traveling, and patients with passive type have no obvious intention to defecate before traveling, which mostly occurs during the daytime and is relatively rare at night. Those with fecal retention (more than 3 days between defecations) mostly show involuntary leakage of small amounts of liquid or paste-like feces.
2. Other clinical manifestations
May be accompanied by involuntary evacuation of gas; may be withdrawn, depressed and irritable.
Examination
1. Physical examination
Anorectal examination may reveal a flaccid anal sphincter or uncoordinated contractions.
2.Laboratory examination
(1) Blood count: White blood cell count is very important for the diagnosis of infection. When the white blood cell count is greater than 10.0×109/L and the proportion of neutrophils is greater than 70%, it suggests the presence of inflammation, which may be caused by gastrointestinal inflammation. If these two indexes are within the normal range, it is necessary to exclude inflammation by combining with the stool routine and endoscopy.
(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 indigestion 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) Electromyography: It can sensitively detect denervation lesions and can often identify myogenic, neurogenic or mixed injuries.
4. Special examination
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 when there is fecal incontinence, and the pressure in the anal canal can be increased when the external anal sphincter is contracted.
Diagnosis
Presence of psychological influences, recurrent uncontrollable defecation with fecal retention for at least 3 months, rectal fingerprinting reveals anal sphincter relaxation, laboratory tests rule out other causes of abnormal defecation disorders, imaging reveals thinning of the sphincter muscle and other pathologies, and anal canal manometry reveals lower than normal pressures while ruling out intracranial lesions, spinal or sacral radiculopathy, and multisystemic disorders (such as Functional fecal incontinence can be diagnosed after excluding intracranial lesions, spinal cord or sacral nerve root lesions, multi-system diseases (e.g., scleroderma) associated with anal sphincter abnormalities, structural abnormalities, or neuropathy.
Differential diagnosis
Functional fecal incontinence should be differentiated from organic incontinence by endoscopy and magnetic resonance imaging (MRI) to determine the presence or absence of organic pathology.
Treatment
Non-surgical treatment is the treatment of choice for fecal incontinence; severe fecal incontinence is usually due to anatomical or neurological damage to the anal sphincter, and requires aggressive surgical treatment.
1.General treatment
(1) Adjustment of defecation habits: regular defecation habits can help to improve intestinal function, which is beneficial to fecal incontinence caused by rectal sensory dysfunction.
(2) Dietary therapy: Increasing dietary fiber intake can enhance the absorption of water in the intestinal tract and help control the symptoms of mild fecal incontinence.
(3) Psychotherapy: Many of the neuropsychiatric symptoms associated with fecal incontinence are psychological in nature, and psychotherapy for these patients will be effective.
(4) Sphincter contraction exercise: by stimulating the anal sphincter or applying glycerin suppositories, patients with overflow incontinence can be benefited.
2. Drug therapy
The most commonly used are antidiarrheal drugs, which work by drugs affecting the transmission of stool to the rectum. For patients with diarrhea, oral antidiarrheal drugs such as loperamide hydrochloride capsules, phenethylpiperidine, montelukast, etc. can be given to normalize the formation of feces, and the adverse effects of the drugs include rash, nausea, dizziness, headache, and fatigue. Anti-diarrhea drugs are only symptomatic treatment, long-term application is not recommended.
3. Biofeedback
If medication is ineffective, biofeedback therapy is recommended. Biofeedback therapy refers to the physiological process of defecation training for patients with fecal incontinence. The purpose of the training is to achieve the contraction of the external anal sphincter during rectal dilatation, which can improve the rectal sensation and the contraction function of the external sphincter at the same time. The method is to equip the patient with a balloon manometry device, connect a pressure monitor, do the contraction of the external anal sphincter, repeat it continuously, then gradually reduce the air volume of the rectal balloon expansion and make the patient always be able to feel the expansion of the rectum, and then no longer consider the pressure monitoring, which can assess the degree of the patient’s threshold for the improvement of the rectal expansion. This method is simple, economical and has no adverse effects.
3. Surgical treatment
Its efficacy in functional fecal incontinence is uncertain. Some studies have shown that the immediate results are good, but the long-term results are not satisfactory.
(1) Colostomy: The last resort for patients with severe fecal incontinence is colostomy. The main objective is to perform a modification of the fecal exit, by making an intestinal stoma, instead of the original anus to exercise the function of defecation. The patient should be evaluated before the operation and antibiotics should be applied to prevent infection, general anesthesia should be adopted during the operation, and intravenous nutrition should be received for a few days after the operation, followed by a gradual resumption of normal diet.
(2) Other surgeries: In addition, implantable sacral nerve stimulation devices can improve rectal sensitivity and bowel control with few complications, but the efficacy of these procedures needs to be evaluated.
Prognosis
The prognosis is related to the patient’s physical condition, the availability of appropriate therapeutic measures and the timeliness of the measures taken.
Care
Long-term bedridden patients with fecal incontinence should change their position, keep the perineum dry and clean, and prevent the perianal skin from being contaminated; patients with pain should correct their bad habit of sitting for a long time.
Prevention
Carry out hygiene education, pay attention to rest, avoid excessive fatigue, maintain a positive and optimistic attitude to develop good defecation habits.