Intestinal tuberculosis is a chronic infectious disease caused by mycobacteria; characterized by the formation of specific granulomas in the intestinal wall with further melting of the focus, the formation of a cavity and fibrosis during sanitation. The clinical picture is characterized by the absence of specific symptoms; pain syndrome, dyspeptic phenomena, intoxication are typical. For diagnosis, an X-ray examination of the intestine, endoscopy with biopsy, tuberculin tests, ultrasound of the abdominal cavity, CT are performed. Therapy includes the use of tuberculostatic drugs, in the presence of complications – surgical treatment.
A18.3 Tuberculosis of the intestine, peritoneum and mesenteric lymph nodes
Intestinal tuberculosis is a relatively rare type of extrapulmonary localization of tuberculosis. Currently, the prevalence of this pathology is about 45 cases per 100 thousand population. Despite the achievements of modern phthisiology, the increase in the incidence of both pulmonary and abdominal tuberculosis continues. The urgency of the problem lies in the fact that there are no screening methods and early clinical symptoms of intestinal tuberculosis. The low symptoms of this form, its course under the guise of other diseases leads to a steady increase in the detection of already neglected forms. Specialists in the field of gastroenterology, phthisiology, surgery are engaged in the study of intestinal tuberculosis.
The cause of the development of this pathology is the ingress of Mycobacterium tuberculosis directly into the intestinal mucosa. Depending on the path of penetration of microorganisms, primary and secondary intestinal tuberculosis are isolated. The first type is extremely rarely registered, which is characterized by the formation of a primary focus of specific inflammation in the mucosa as a result of microorganisms entering the gastrointestinal tract from the outside (for example, when drinking infected milk).
The realization of infection with secondary intestinal tuberculosis is possible in three ways: hematogenic, lymphogenic and deglutational. The deglutational mechanism of infection consists in ingestion of sputum containing a large number of bacteria in the presence of pulmonary tuberculosis with foci of decay. Previously, this path of pathology development was considered the main one, and intestinal tuberculosis was considered as the final stage of the general disease. Currently, an important role in the formation of intestinal tuberculosis is assigned to the hematogenic and lymphogenic pathways (lesions in the intestine are diagnosed in patients with tuberculosis of the genitourinary, bone and joint systems).
For the formation of a focus of specific tuberculous inflammation in the intestine, it is not enough only to get microorganisms. Pathology develops with a violation of local and general resistance (the risk increases with nonspecific diseases of the gastrointestinal mucosa, inflammatory and degenerative changes in the nervous apparatus of the intestinal wall).
A feature of the clinical picture of intestinal tuberculosis is the absence of specific symptoms. An asymptomatic course is also possible when the diagnosis is established by the results of an autopsy. The first signs of pathology may appear a long time after infection (from a year to 10-15 years). The symptoms are determined by the stage of the process, the prevalence and localization of the lesion.
At the first stage of the development of the disease, granulomas form under the epithelium of the mucous membrane. During this period, the clinical picture is characterized by low-intensity abdominal pain that does not have a clear localization. Dyspeptic phenomena are possible: nausea, stool disorders (constipation, followed by diarrhea). Further development of the pathological process is accompanied by caseous decay of foci; the pain syndrome becomes more pronounced, the pain is constant, most often localized in the right iliac region (intestinal tuberculosis in most cases affects the ileocecal region), is not associated with food intake.
Signs of intoxication are added: the patient notes pronounced general weakness, malaise, the temperature rises to subfebrile figures, weight decreases. The clinical picture of intestinal tuberculosis is characterized by a change in the phases of exacerbation and subsiding: episodes of hyperthermia and increased dyspeptic phenomena periodically occur.
In the absence of adequate treatment and the progression of a specific process, perforation of the affected area of the intestine, the development of limited or diffuse peritonitis is possible. When the appendix is affected, symptoms of acute appendicitis occur. When the focus breaks into the intestinal cavity, there is abundant diarrhea with an admixture of blood, which is not amenable to anti-inflammatory and antidiarrheal treatment. If mesenteric lymph nodes are involved in the pathological process, the patient notes the appearance of constant intense dull pains in the navel area, which increase with a change of body position, physical exertion. Symptoms of intoxication are increasing.
In identifying this pathology, an important role is played by the alertness of specialists regarding intestinal tuberculosis, a detailed examination of patients with undefined symptoms of intestinal damage, pain in the right iliac region. Consultation with a gastroenterologist suggests the presence of specific inflammation. At the beginning of the disease, diagnosis is difficult because there are no specific studies to verify intestinal tuberculosis. At the same time, the paucity of symptoms leads to the fact that patients are treated already at late stages, when caseous necrosis takes place.
- Laboratory tests. In clinical blood tests, leukocytosis in neutrophil shift, eosinophilia, lymphopenia, acceleration of ESR are determined. Dysproteinemia is detected. Coprological examination makes it possible only to establish the type of digestive disorders, mycobacteria in feces are extremely rarely detected.
- Tuberculin samples. The Mantoux reaction in the diagnosis of intestinal tuberculosis is of some importance, but it is positive in less than half of cases. Enzyme immunoassay blood tests – quantiferon and T-Spot.TB have greater specificity.
- X-ray examination. The detection of calcified lymph nodes on an overview abdominal organs x-ray indicates a specific mesadenitis. Radiography of the intestine with contrast gives information about the localization, prevalence and type of lesion. With ulcerative defects, the symptom of a “niche” is determined; with a hypertrophic type of inflammation, a bumpy infiltrate is detected; the affected part of the intestine has uneven contours, is deformed, the folds are thickened, smoothed; ulceration and narrowing of the ileum are visualized. When inflated with gas, the intestine is rigid, its mobility is limited by peritoneal accretions. The difference between the X-ray picture of intestinal tuberculosis from that of nonspecific ulcerative colitis is the alternation of the affected areas of the intestine with healthy ones.
- Endoscopic examination of the intestine. During colonoscopy, various changes are detected: irregular ulcers, rigidity of the walls, narrowing of the intestinal lumen, pseudopolypes. To verify the diagnosis, an endoscopic biopsy is performed with a histological examination of the tissue. However, this method of investigation is not always informative: with submucosal localization of the process or insufficiently deep biopsy, only a picture of nonspecific inflammation in the biopsy is possible. In some cases, diagnostic laparoscopy is performed.
To clarify the diagnosis and localization of the process, CT and abdominal ultrasound can be performed, but these methods do not have independent significance. Differential diagnosis of intestinal tuberculosis is carried out with nonspecific ulcerative colitis, Crohn’s disease, appendicitis, malignant neoplasms, intestinal amyloidosis.
Treatment of patients with verified intestinal tuberculosis is carried out in specialized departments of tuberculosis dispensaries. Drugs are used: isoniazid, rifampicin, PASC, ftivazid. Due to the prevalence of resistant forms of mycobacteria, it is advisable to prescribe two drugs simultaneously. In the absence of effectiveness, second-line drugs are prescribed: cycloserine, ethambutol, ethionamide. Treatment with tuberculostatic drugs is carried out for one and a half to two years until the complete disappearance of clinical symptoms.
Treatment of intestinal tuberculosis also includes diet therapy. Food is prescribed with a sufficient amount of proteins, carbohydrates, fats, and high nutritional value. Additionally, vitamin therapy is carried out. With the development of complications (intestinal perforation, bleeding, fistula formation, intestinal obstruction, peritonitis), surgical treatment is performed.
Prognosis and prevention
The prognosis for this disease is unfavorable. This is due to the predominant detection of advanced forms of intestinal tuberculosis, a high percentage of patients who independently stop treatment due to side effects or indiscipline, a large number of complications, including narrowing of the intestinal lumen with obstruction, the presence of resistance of mycobacteria to chemotherapy drugs. A more favorable prognosis for the defeat of the large intestine, since it is possible to perform extensive resection.
Specific prevention of tuberculosis, including abdominal localization, consists in BCG vaccination (the effectiveness reaches 80%). Persons with immunodeficiency or receiving immunosuppressive therapy should be under the supervision of phthisiologists. Specific chemoprophylaxis (oral administration of isoniazid for a year) is prescribed to people who have contact with a patient with an open form of tuberculosis, as well as with a positive result of tuberculin tests.