Irritable bowel syndrome

Irritable Bowel Syndrome (IBS) is a functional disease of the gastrointestinal tract, characterized by pain and / or discomfort in the abdomen, which pass after the act of defecation.

These symptoms are accompanied by a change in the frequency and consistency of the stool and are combined with at least two persistent symptoms of bowel dysfunction:

• change in the frequency of the stool (more often 3 times a day or less than 3 times a week);
• change in the consistency of feces (lumpy, dense stools or watery stools);
• changing the act of defecation;
• imperative urges;
• a feeling of incomplete emptying of the intestine;
• the need for additional efforts during defecation;
• secretion of mucus with feces;
• bloating, flatulence;
• rumbling in the abdomen.

The duration of these disorders should be at least 12 weeks during the last 12 months. Among the disorders of the act of defecation, special importance is given to imperative urges, tenesms, a feeling of incomplete bowel movement, additional efforts during defecation (Roman criteria II).

The cause is unknown, and pathophysiology is not fully understood. The diagnosis is established clinically. Treatment is symptomatic, consisting of dietary nutrition and drug therapy, including anticholinergic drugs and substances that activate serotonin receptors.

Irritable bowel syndrome is the diagnosis of exclusion, i.e. Its establishment is possible only after the exclusion of organic diseases.

ICD-10 code

K58 Irritable bowel syndrome.

Epidemiology of irritable bowel syndrome

Irritable bowel syndrome is particularly widespread in industrialized countries. According to world statistics, 30 to 50% of patients who go to gastroenterological rooms, suffer from irritable bowel syndrome; presumably 20% of the world's population have symptoms of irritable bowel syndrome. Only 1/3 of the patients apply for medical care. Women are sick 2-4 times more often than men.

After 50 years, the ratio of men and women is close to 1: 1. The occurrence of the disease after 60 years is doubtful.

[1], [2], [3], [4], [5], [6], [7], [8],

What causes irritable bowel syndrome?

The cause of irritable bowel syndrome (IBS) is unknown. There was no pathological cause. Emotional factors, diet, medications or hormones can accelerate and aggravate manifestations of the gastrointestinal tract. Some patients have anxious conditions (especially panic anxiety, major depressive syndrome and somatization syndrome). However, stress and emotional conflict do not always coincide with the onset of the manifestation of the disease and its relapse. Some patients with irritable bowel syndrome have symptoms identified in the scientific literature as symptoms of atypical painful behavior (that is, they express an emotional conflict in the form of complaints of GI disorders, usually abdominal pain). A doctor who examines patients with irritable bowel syndrome, especially those who are resistant to treatment, should investigate unsolved psychological problems, including the possibility of sexual or physical abuse.

There are no persistent violations of motility. In some patients, there is a disturbance of the gastrointestinal reflex with delayed, prolonged colonic activity. In this case, there may be a delay in evacuation from the stomach or a violation of the motility of the jejunum. Some patients do not have objectively proven violations, and in those cases where violations have been identified, direct correlation with symptoms may not be observed. Passage through the small intestine changes: sometimes the proximal segment of the small intestine shows hyperreactivity to food or to parasympathomimetics. The study of intestinal pressure of the sigmoid colon showed that the functional stool delay can be combined with the hyperreactive segmentation of the haustra (ie, increased frequency and amplitude of contractions). On the contrary, diarrhea is associated with a decrease in motor function. Thus, strong cuts can accelerate or delay passage from time to time.

Excess mucus production, which is often observed in irritable bowel syndrome, is not associated with mucosal lesions. The reason for this is unclear, but may be associated with cholinergic hyperactivity.

There is a hypersensitivity to normal stretching and increased lumen of the gut, as well as an increase in pain sensitivity with normal gas accumulation in the intestine. Pain, most likely, is caused by pathologically severe contractions of the smooth muscles of the intestine or increased sensitivity of the intestine to stretching. Hypersensitivity to hormones gastrin and cholecystokinin may also be present. However, hormonal fluctuations do not correlate with symptoms. High-calorie food can lead to an increase in the magnitude and frequency of electrical activity of smooth muscles and gastric motility. Fatty foods can cause a delayed peak in motor activity, which can be significantly increased in irritable bowel syndrome. The first few days of menstruation can lead to a transient increase in prostaglandin E2, which is likely to stimulate pain and diarrhea.

Symptoms of irritable bowel syndrome

Irritable bowel syndrome tends to start in adolescents and young people, debuting with symptoms that have an irregular recurrent nature. The development of the disease in adults is not uncommon, but occurs infrequently. Symptoms of irritable bowel syndrome rarely appear at night, they can be caused by stress or food intake.

Features of irritable bowel syndrome include abdominal pain associated with delayed bowel movements, changes in stool frequency or consistency, bloating, mucus in the stool, and a feeling of incomplete emptying of the rectum after defecation. In general, the character and localization of pain, provoking factors and the nature of the stool, are different for each patient. Changes or abnormalities from common symptoms suggest an intercurrent disease and these patients should undergo a complete examination. Patients with irritable bowel syndrome may also have extra-intestinal symptoms of irritable bowel syndrome (eg, fibromyalgia, headaches, dysuria, temporomandibular joint syndrome).

Two main clinical types of irritable bowel syndrome have been described.

In irritable bowel syndrome with a predominance of stool retention (irritable bowel syndrome with predominance of constipation), most patients experience pain in more than one area of the large intestine with periods of stool delay alternating with normal frequency. The stool often contains clear or white mucus. The pain has a paroxysmal character such as colic or the character of aching pain; pain syndrome may decrease after defecation. Eating usually causes symptoms. Bloating, frequent gas leakage, nausea, dyspepsia and heartburn may also occur.

Irritable bowel syndrome with a predominance of diarrhea is characterized by imperative diarrhea, which develops immediately during or after a meal, especially with fast food intake. Night diarrhea is rare. Typical pain, bloating and sudden desires on the chair, it is possible to develop incontinence stool. Painless diarrhea is uncharacteristic, this should cause the doctor to consider other possible causes (eg, malabsorption, osmotic diarrhea).

Diagnosis of irritable bowel syndrome

Diagnosis of irritable bowel syndrome is based on the characteristic intestinal manifestations, the nature and timing of the onset of pain and exclusion of other diseases in the case of a physical and standard instrumental examination. The diagnostic test should be as fast as possible in case of risk factors ("anxiety symptoms"): old age, weight loss, rectal bleeding, vomiting. The main diseases that can simulate irritable bowel syndrome include lactose intolerance, diverticular disease, medical diarrhea, biliary tract diseases, laxative abuse, parasitic diseases, bacterial enteritis, eosinophilic gastritis or enteritis, microscopic colitis and inflammatory bowel diseases.

Hyperthyroidism, carcinoid syndrome, medullary thyroid cancer, vipoma and Zollinger-Ellison syndrome are additional possible causes of diarrhea in patients. The bimodal age distribution of patients with inflammatory bowel disease allows evaluation of groups of young and older patients. Patients over 60 years of age should be excluded from ischemic colitis. Patients with stool delay and absence of anatomical reasons should be examined for hypothyroidism and hyperparathyroidism. If symptoms suggest malabsorption, sprue, celiac disease and Whipple's disease, further examination is necessary. Examination of cases of stool retention in patients with complaints about the need for severe straining during defecation (eg, dysfunction of the pelvic floor muscles) is required.

[9], [10], [11], [12], [13], [14], [15], [16], [17]

Anamnesis

Particular attention should be paid to the nature of pain, bowel characteristics, family history, the drugs used and the nature of nutrition. It is also important to evaluate individual patient problems and their emotional status. The patient's patience and perseverance is the key to effective diagnosis and treatment.

Based on the symptoms, Roman criteria for the diagnosis of irritable bowel syndrome are developed and standardized; the criteria are based on the presence, for at least 3 months, of the following:

1. abdominal pain or discomfort that decrease after defecation or are associated with a change in stool frequency or consistency,
2. violation of defecation, characterized by at least two of the following symptoms: a change in the frequency of the stool, changing the shape of the stool, changing the nature of the stool, the presence of mucus and bloating, or a feeling of incomplete emptying of the rectum after defecation.

[18], [19], [20], [21], [22], [23], [24]

Physical examination

In general, the patient's condition is satisfactory. Palpation of the abdomen can reveal soreness, especially in the left lower quadrant, associated with palpation of the sigmoid colon. All patients should undergo a digital rectal examination, including a fecal occult blood test. In women, pelvic examination (bimanual vaginal examination) helps to exclude tumors and ovarian cysts or endometriosis, which can simulate irritable bowel syndrome.

Instrumental Diagnosis of Irritable Bowel Syndrome

It is necessary to perform proctosigmoscopy with a flexible endoscope. The introduction of a sigmoidoscope and insufflation of air often cause bowel spasm and pain. Mucous and vascular pattern in irritable bowel syndrome is usually not changed. Colonoscopy is more preferable in patients older than 40 years with complaints suggesting changes in the colon and especially in patients without previous symptoms of irritable bowel syndrome in order to exclude polyposis and large intestine tumors. In patients with chronic diarrhea, especially elderly women, mucosal biopsy can rule out possible microscopic colitis.

In many patients with irritable bowel syndrome, as a rule, an excessive diagnostic examination is performed. Patients whose clinical picture corresponds to the Roman criteria, but who do not have any other symptoms or signs indicating a different pathology, the results of laboratory tests for diagnosis do not affect. If the diagnosis is questionable, the following tests should be performed: a general blood test, an ESR, a biochemical blood test (including functional hepatic tests and serum amylase ), a urine test, and a thyroid stimulating hormone level.

Additional research

(Ultrasound, CG, irrigoscopy, esophagogastroduodenoscopy and X-ray of the small intestine are also shown in case of uncertainty in the diagnosis of irritable bowel syndrome, detection of other symptoms and dysfunctions.If the structural changes in the small intestine are diagnosed, the H2-respiratory test is performed Bacterial stool or stool examination helminthic and parasitic infestations are rarely positive in the absence of an anamnesis for previous trips or specific signs (eg, fever, blood liquid stool, acute onset of severe diarrhea).

[25], [26], [27]

Intercurrent disease

The patient may develop other gastrointestinal disorders that are not characteristic of the irritable bowel syndrome, and the clinician should consider these complaints. Changes in symptoms (eg, in the localization, nature or intensity of pain, in the bowel condition, in palpation-induced stool and diarrhea delay) and the appearance of new signs or complaints (eg, night diarrhea) may signal the presence of another disease. New symptoms that require additional testing include: fresh blood in the stool, weight loss, severe abdominal pain or unusual abdominal enlargement, steatorous or fetid stool, fever, chills, persistent vomiting, hematomasis, symptoms that disturb sleep (eg, pain, desires on a chair), as well as persistent progressive deterioration of the condition. In patients older than 40 years, the development of somatic pathology is more likely than in young adults.

Treatment of irritable bowel syndrome

Treatment of irritable bowel syndrome is symptomatic and palliative. Sympathy and psychotherapy are of paramount importance. The doctor should explain the main reasons and convince the patient of the absence of somatic pathology. This involves explaining the normal physiology of the intestine, paying special attention to the intestinal hypersensitivity, the effect of food or medication. Such explanations form the basis for the appointment of regular, standard, but individual therapy. It should be emphasized the prevalence, chronic nature and the need to continue treatment.

In case of psychological overstrain, anxiety or mood changes, evaluation of the condition and appropriate therapy are necessary. Regular physical activity helps reduce stress and improve bowel function, especially in patients with stool delay.

Nutrition and irritable bowel syndrome

In general, normal nutrition should be maintained. Food should not be excessively abundant, and eating is unhurried and measured. Patients with bloating and increased gas production should limit or rule out the use of beans, cabbage and other foods containing carbohydrates that are amenable to microbial intestinal fermentation. Reducing the consumption of apples and grape juice, bananas, nuts and raisins can also reduce flatulence. Patients with signs of lactose intolerance should reduce the consumption of milk and dairy products. Abnormal bowel function may be due to eating foods that contain sorbitol, mannitol or fructose. Sorbitol and mannitol are artificial sugar substitutes used in diet food and chewing gum, while fructose is a common element of fruits, berries and plants. Patients with postprandial abdominal pain can be recommended a low-fat diet with high protein content.

Dietary fiber can be effective because of water absorption and softening of the stool. It is indicated for patients with a delayed stool. Soft calorie-forming substances can be used [eg, raw bran, starting with 15 ml (1 table spoon) at each meal, with increased fluid intake]. Alternatively, a hydrophilic psyllium mucilloid with two glasses of water can be used. However, excessive use of fiber can lead to bloating and diarrhea. Therefore, the amount of fiber should be adapted to individual needs.

Drug treatment of irritable bowel syndrome

Medicamental treatment of irritable bowel syndrome is undesirable, except for short-term use during periods of exacerbation. Anticholinergic drugs (eg, hyoscyamine 0.125 mg for 30-60 minutes before meals) can be used as antispastic agents. New selective antagonists of M muscarinic receptors, including zamifenacin and darifenacin, have less cardiac and gastric side effects.

Serotonin receptor modulation may be effective. The 5HT4 receptor agonists tegaserod and prucalopride can be effective in patients with stool delay. 5HT4 receptor antagonists (eg, alosetron) can benefit patients with diarrhea.

Patients with diarrhea before meals can be administered orally diphenoxylate 2.5-5 mg or loperamide 2-4 mg. However, the continued use of antidiarrheal drugs is undesirable because of the development of tolerance to drugs. In many patients, tricyclic antidepressants (eg, desipramine, imizine, amitriptyline 50-150 mg orally once a day) reduce the symptoms of stool and diarrhea delay, abdominal pain and flatulence. These medications are supposed to reduce pain through the post-activation activation of the spinal cord and cortical afferent impulses coming from the intestine. Finally, to relieve the irritable bowel syndrome, certain aromatic oils that contribute to the escape of gases can help to relieve spasm of smooth muscles and reduce the pain syndrome in some patients. Peppermint oil is the most commonly used drug of this group.

[28], [29], [30], [31], [32], [33], [34]