Irritable Bowel Syndrome Diagnosis

Survey plan with irritated bowel

The diagnosis of irritable bowel syndrome is an exception diagnosis. Preliminary diagnosis is based on the Roman criteria II (1999).

Pain and / or discomfort in the abdomen for 12 weeks, not necessarily consecutive, in the last 12 months:

• their severity decreases after defecation; and / or associated with changes in the frequency of defecation;
• and / or are associated with changes in the consistency of the stool, and

Two or more of the following:

• altered frequency of bowel movements (more often 3 times a day or less than 3 times a week);
• altered stool consistency (lumpy, dense stools or watery stools);
• change in the passage of the stool (tension during defecation, urgent urge to defecate, feeling of incomplete evacuation);
• a passage of mucus and / or flatulence or a sensation of bloating.

The final diagnosis is made by eliminating organic pathology. For the application of the Roman criteria II, the absence of so-called "anxiety symptoms" is necessary. In this case, the sensitivity of the criteria is 65%, the specificity is 95%.

"Symptoms of anxiety", excluding the diagnosis of irritable bowel syndrome

Anamnesis	Weight loss The appearance of symptoms older than 50 years Symptomatics at night, forcing the patient to get up in the toilet Weighed down family history of cancer and inflammatory diseases of the colon Constant intense pain in the abdomen as the only and leading symptom of the defeat of the gastrointestinal tract The recent use of antibiotics
Inspection data	Fever Hepatomegaly, splenomegaly
Laboratory and instrumental data	The presence of latent blood in the stool Reduced hemoglobin concentration Leukocytosis Increased ESR Biochemical changes in blood

In the presence of "symptoms of anxiety," careful laboratory-instrumental examination of the patient is necessary.

Laboratory research

Compulsory laboratory tests

Carried out to exclude "symptoms of anxiety" and diseases that occur with a similar clinical picture.

• General blood analysis. Carried out for the exclusion of inflammatory or paraneoplastic genesis of pain abdominal syndrome.
• Analysis of feces for the intestinal group of pathogenic bacteria (Shigella, Salmonella, Yersinia), eggs of worms and parasites. The study is carried out three times.
• Coprogram.
• General urine analysis.
• Concentration of serum albumin.
• The content in the blood of potassium, sodium, calcium.
• Proteinogram.
• Research of blood immunoglobulins.
• Concentration in the blood of thyroid hormones.

For irritable bowel syndrome, there is no change in laboratory tests.

Additional laboratory tests

Conducted to identify concomitant diseases of the hepatobiliary system.

• Serum aminotransferase, GGTF, alkaline phosphatase.
• Concentration of total bilirubin.
• Study for hepatitis virus markers: HBAg, Anti-HCV.

Instrumental research

Compulsory instrumental research

• Irrigoscopy: typical signs of dyskinesia - uneven filling and emptying, alternation of spastic reduced and extended areas and / or excessive secretion of fluid in the lumen of the intestine.
• Colonoscopy with biopsy is an obligatory method of research, since it allows the study of organic pathology. In addition, only a morphological study of the biopsy specimens of the intestinal mucosa allows ultimately to distinguish irritable bowel syndrome from inflammatory bowel diseases. The study often provokes the symptoms of the disease due to the characteristic for the irritable bowel syndrome of visceral hypersensitivity. PHAGS with biopsy of the small intestine mucosa: conducted to exclude celiac disease.
• Ultrasound of the abdominal cavity: allows excluding cholelithiasis, cysts and calcifications in the pancreas, volumetric abdominal cavities.
• A test with lactose load or a diet with the exception of lactose for 2-3 weeks: for the diagnosis of latent lactase deficiency.

Additional instrumental research

Conducted in order to detail the changes found during the conduct of mandatory research methods.

• RKT.
• Doppler study of the vessels of the abdominal cavity.

Differential diagnosis of irritable bowel

Irritable bowel syndrome must be differentiated from the following diseases and conditions:

• neoplasms of the large intestine; inflammatory bowel diseases; diverticular disease; dysfunction of the pelvic floor muscles;
• neurological diseases (Parkinson's disease, autonomic dysfunction, multiple sclerosis);
• side effects of medications (opiates, calcium channel blockers, diuretics, anesthetics, muscle relaxants, holinoblokatory); hypothyroidism and hyperparathyroidism.

Symptoms similar to the clinical picture of irritable bowel syndrome are observed when:

• physiological conditions in women (pregnancy, menopause);
• the use of certain products (alcohol, coffee, gas-producing products, fatty foods) - can cause both diarrhea and constipation;
• change the habitual way of life (for example, business trips);
• presence of ovarian cysts and uterine fibroids.

In patients with a predominance in the clinical picture of constipation, it is necessary to exclude obstruction of the colon, primarily of a tumor nature. This is especially true in patients older than 45 years, as well as in young patients with:

1. debut disease;
2. expressed or refractory to the treatment of symptoms;
3. family history of colon cancer.

With the prevalence of diarrheal syndrome in symptoms, irritable bowel syndrome must be differentiated from the following diseases.

• Inflammatory bowel disease: Crohn's disease, ulcerative colitis.
• Infectious diseases caused by Lamblia intestinalis, Entamoeba histolytica, Salmonella, Campylobacter, Yersinia, Clostridium difficile, parasitic infestations.
• Side effects of medications (antibiotics, potassium preparations, bile acids, misoprostol, abuse of laxatives).
• Malabsorption syndrome: sprue, lactase and disaccharidase insufficiency.
• Hyperthyroidism, carcinoid syndrome, medullary thyroid cancer, Zollinger-Ellison syndrome.
• Other causes: post-gastrectomy syndrome, enteropathy associated with HIV infection, eosinophilic gastroenteritis, food allergy.

If the pain syndrome prevails in the clinical picture, irritable bowel syndrome should be differentiated from the following states:

• partial obstruction of the small intestine;
• Crohn's disease; ischemic colitis;
• chronic pancreatitis;
• lymphoma of the digestive tract;
• endometriosis (symptoms usually occur during menstruation);
• diseases of the biliary tract.

For a differential diagnosis, colonoscopy with biopsy is very important.

Indications for consultation of other specialists

• Infectionist - with a suspicion of the infectious nature of diarrhea.
• Psychiatrist (psychotherapist) - for the correction of psychosomatic disorders.
• Gynecologist - to exclude the causes of pain syndrome associated with gynecological diseases.
• Oncologist - in case of detection of malignant neoplasms during instrumental research.

[1], [2], [3], [4], [5], [6], [7], [8], [9], [10]