What Is Intestinal Pseudoobstruction?

Pseudo-intestinal obstruction (IPO) is a disorder of the motor function of the intestinal wall due to neurosuppression, toxin stimulation or lesions of the intestinal smooth muscle itself. Clinically, there are symptoms and signs of intestinal obstruction, but there are no mechanical intestinal obstruction factors inside and outside the intestine, so it is also called dynamic intestinal obstruction, which is a syndrome without intestinal obstruction. According to the course of disease, there are acute and chronic. Paralytic intestinal obstruction and spastic intestinal obstruction belong to acute pseudointestinal obstruction. Chronic pseudointestinal obstruction has two types: primary and secondary. The disease can occur at any age, with more women than men and a family history.

Basic Information

nickname

Dynamic intestinal obstruction

English name

pseudoileus

Visiting department

Gastroenterology

Multiple groups

female

Common causes

Nervous suppression, toxin stimulation, or pathological changes in the smooth muscle of the bowel

Common symptoms

Chronic or recurrent nausea, vomiting, abdominal pain, bloating

Causes of pseudointestinal obstruction

It is generally believed that chronic pseudointestinal obstruction is caused by intestinal muscle or neurogenic lesions and can be divided into the following two categories.

Primary chronic pseudointestinal obstruction

Also known as chronic idiopathic pseudointestinal obstruction, its etiology is unclear and may be related to chromosomal dominant inheritance. Many patients have a family history and can affect some organs other than the gastrointestinal tract (such as the bladder), so some people call it familial visceral myopathy or hereditary jejunal visceral myopathy, which can be divided into the following according to the condition of the intestinal wall: 3 types.

(1) Myopathic pseudointestinal obstruction (visceral myopathy) is mainly in the smooth muscle of the intestinal wall and can be divided into familial or sporadic. The main pathological change is the degenerative change of the circular or longitudinal muscles of the intestinal wall, the latter Worse, sometimes the muscles are completely atrophied and replaced by collagen.

(2) The neuropathic pseudointestinal obstruction (visceral neuropathy) lesions are mainly in the nerves of the intestinal wall muscle plexus, which are sporadic or familial, and the pathological changes mainly occur in the intestinal wall muscle plexus, showing neurons and Degeneration and swelling of neuronal processes, and some cases involve other parts of the nervous system.

(3) Acetylcholine receptor dysfunction Pseudointestinal obstruction No organic abnormalities of muscle or nerve are found, but physiological tests have determined abnormalities of intestinal motor function, and some cases may occur with muscarinic acetylcholine receptors of intestinal smooth muscle Functional defects related.

2. Secondary chronic pseudointestinal obstruction

Most of the diseases and drugs related to chronic pseudointestinal obstruction are secondary to other diseases or caused by drug abuse:

(1) Small intestinal smooth muscle disease collagen vascular disease scleroderma, progressive systemic sclerosis, dermatomyositis, polymyositis, systemic lupus erythematosus; invasive muscle disease amyloidosis; primary muscle Diseases Ankylosal muscular dystrophy, progressive muscular dystrophy; other waxy pigmentation, non-tropical stomatitis and diarrhea.

(2) Endocrine diseases Hypothyroidism ; Diabetes ; Pheochromocytoma .

(3) Neurological diseases Parkinson's disease, familial autonomic dysfunction, Hirshsprung disease, Chang disease, psychiatric disease, small bowel ganglia disease.

(4) Medicinal reasons Toxic drug lead poisoning, mushroom poisoning; Drug side effects phenothiazines, tricyclic antidepressants, antiparkinsonian drugs, ganglion blockers, clonidine.

(5) Electrolyte disorders Hypokalemia, hypocalcemia, hypomagnesemia, uremia.

(6) Other jejunum-ileal bypass, jejunal diverticulum, spinal cord injury, malignant tumor.

Among them, chronic pseudointestinal obstruction caused by systemic sclerosis is more common. Its main pathological changes are atrophy and fibrosis of smooth muscle of the intestinal wall, and lesions of the circular muscles are even more significant. Amyloidosis can be seen in the muscle layer of the intestine with a large amount of starch Mucosal edema is present in the intestinal muscularis of the intestinal wall. Diabetes often does not change significantly in the intestinal wall muscles and myenteric plexus.

Clinical manifestations of pseudointestinal obstruction

Mainly manifested by chronic or recurrent nausea, vomiting, abdominal pain and bloating. Abdominal pain is often located in the upper abdomen or around the umbilicus, and is persistent or paroxysmal, often accompanied by varying degrees of diarrhea or constipation, and some diarrhea and constipation appear alternately. May have difficulty swallowing, urinary retention, incomplete bladder emptying and repeated urethral infections, dysfunction of temperature regulation, dilated pupils, etc. On physical examination, she had abdominal distension and tenderness, but no muscle tension. Vibration sounds could be heard, and bowel sounds weakened or disappeared. Weight loss and malnutrition are common. The diagnosis of this disease is difficult, and it is often considered when the cause of mechanical intestinal obstruction is not found after repeated laparotomy.

False intestinal obstruction

Abdominal X-ray images do not show the flatulence and gas-liquid levels caused by mechanical intestinal obstruction; gastrointestinal manometry showed abnormalities in the esophagus and gastrointestinal tract; small intestinal histological examination was positive for Smith silver staining, which could confirm the diagnosis. If it is necessary to distinguish between pseudo-intestinal obstruction and mechanical intestinal obstruction, a small intestine barium enema can be performed. The method is to insert a soft catheter with a copper ball through the mouth to the proximal side of the jejunum and inject the barium agent for fluoroscopy or photography. Film, this method has a diagnosis rate of 98% for small intestinal organic lesions. If it is a pseudointestinal obstruction, no organic obstructive lesions are visible.

Diagnosis of pseudo-intestinal obstruction

Patients with intestinal obstruction should consider the possibility of this disease if they have one or more of the following conditions.

1. Intestinal obstruction symptoms begin to appear in children or adolescence, and abdominal distension cannot completely disappear during the intermittent period of intestinal obstruction.

2. There are similar patients in the family.

3. Difficulty swallowing or weak urination.

4. Cachexia.

5. Suffering from a disease that can cause pseudointestinal obstruction or taking drugs that may cause pseudointestinal obstruction.

6. Jejunal diverticulosis.

7. Signs of Raynaud or scleroderma.

Complications of pseudointestinal obstruction

Pseudointestinal obstruction may have difficulty swallowing when the esophagus is involved; bladder involvement may have urinary retention; ocular muscle paralysis may be involved when the eye muscles are involved, and the upper eyelids are drooping. Chronic pseudo-intestinal obstruction may cause malnutrition such as anemia and hypoproteinemia due to malabsorption.

Treatment of pseudo-intestinal obstruction

Non-surgical treatment

There is currently no specific treatment for this disease. Comprehensive treatments such as reducing intestinal dilatation, using antibiotics, restoring normal gastrointestinal motility and total parenteral nutrition can be taken.

(1) Diet therapy requires a low-fat, low-lactose, and low-fiber diet. Fat is not more than 40g, and preferably long-chain fat, lactose is not more than 0.5g / 100cal, and fiber is not more than 1.5g / 100cal. Because the patient's symptoms and signs are closely related to the degree of intestinal expansion, and the degree of intestinal expansion is related to the volume and type of food ingested, poorly absorbed fat can be broken down into fatty acids by bacteria in the small intestine, which stimulates large intestinal fluid secretion and expands the small intestine . This disease is often accompanied by different degrees of small intestinal mucosal damage, which affects the catabolism of lactose, thereby increasing intestinal gas production and fluid secretion, and aggravating small intestine expansion. In addition, long-term food accumulation in the intestinal loop with peristaltic dysfunction, especially foods rich in cellulose can form fecal stones, which can produce mechanical intestinal obstruction on the basis of pseudointestinal obstruction, and appropriate supplementation of vitamin B ₁₂ , vitamin D, and vitamins K and trace elements, etc., should be fasted in acute episodes, continuous gastrointestinal decompression.

(2) Antibiotic treatment of intestinal bacterial over-production can cause fat malabsorption and steatosis. Treatment with antibiotics can reduce symptoms. The choice of antibiotics is best based on the results of intestinal fluid culture.

(3) The purpose of drug therapy is to stimulate the small intestine to contract and restore the normal small intestinal motility function. Cisapride is a new non-cholinergic stimulant. It selectively acts on the gastrointestinal tract and releases acetylcholine from the myenteric plexus, thereby increasing muscle contraction and avoiding systemic side effects. it is good. Erythromycin has a motilin-like effect, can effectively promote gastrointestinal motility, and has a certain effect in the treatment of pseudo small intestinal obstruction.

(4) Total parenteral nutrition (TPN) due to the disease has different degrees of malabsorption and malnutrition, coupled with poor diet and drug treatment, surgery is only effective for some patients. Therefore, most patients need TPN treatment, especially in severe cases. Long-term TPN treatment is the only way to maintain life.

2. Surgical treatment

Once the disease is diagnosed, surgery is not performed in principle, but laparotomy is necessary when symptoms persist and mechanical intestinal obstruction cannot be completely ruled out. If the cause of mechanical intestinal obstruction is not found during the operation, a full-thickness resection of the intestinal segment of the disease should be performed and a histological examination should be performed to determine the nature. Different surgical methods are used for different parts of the disease. When the symptoms of the esophagus are predominant, balloon dilatation is feasible; when the symptoms of the stomach are predominant, the vagus nerve is cut and the antrum is removed, and the gastric jejunum Roux-en-Y anastomosis is available. When the duodenum is mainly dilated, small bowel suspension fistula decompression can be used, and TPN is more effective. It has been reported that small intestine fistula combined with intestinal stimulants can restore the contractile capacity of intestinal smooth muscle in patients with myopathic pseudointestinal obstruction. If the lesion is limited to a small intestine, short-circuit surgery is feasible. Radical resection of the intestinal segment of the disease is More ideal treatment. If the small bowel disease is extensive, long-term TPN treatment is needed after the small bowel resection, which is actually difficult to achieve. For severe patients, small bowel transplantation may be a promising treatment method, but there are only animal experiments and no clinical application. Report.

Prognosis of pseudointestinal obstruction

The prognosis of acute pseudointestinal obstruction is better. With the cure of the primary disease and active treatment, acute pseudointestinal obstruction can be cured quickly. However, it must be emphasized that early detection, early treatment, and timely treatment can cause perforation.