TB



Overview.

Definition

Intestinal tuberculosis is a chronic specific infection caused by Mycobacterium tuberculosis humanum invading the intestinal tract, mostly secondary to pulmonary tuberculosis.

Disease classification

According to pathologic classification, intestinal tuberculosis can be divided into the following 3 categories.

Ulcerative type of intestinal tuberculosis

The main pathological change is intestinal ulcer.

It is usually not accompanied by intestinal hemorrhage or acute perforation, but an abdominal abscess may be formed as a result of chronic perforation.

The process of tissue repair can result in scar formation, causing intestinal stenosis.

Proliferative intestinal tuberculosis

The main pathologic change is hyperplasia.

The intestinal wall may become thicker and harder due to the proliferating fibrous tissue.

This type of intestinal tuberculosis can cause narrowing of the intestinal lumen, resulting in obstruction.

Mixed type of TB

Both of the above pathologic changes are present at the same time.

Morbidity

In recent years, with the improvement of living and sanitary conditions in cities and towns in China, the incidence of tuberculosis has decreased significantly. As a result, the incidence of this disease has also gradually decreased. However, there is a trend of “resurgence” of tuberculosis at present.

The incidence of the disease is equal between men and women, with women slightly more common than men, but there is no significant gender difference.

The disease can occur at any age, but is most common in young adults.

Causes

Causative factors

Basic Causes

Intestinal tuberculosis is mainly a chronic specific infection caused by the invasion of Mycobacterium tuberculosis into the intestinal tract. Infected Mycobacterium tuberculosis is categorized into human-type Mycobacterium tuberculosis and bovine-type Mycobacterium tuberculosis.

Mycobacterium tuberculosis human type: intestinal tuberculosis is mainly caused by Mycobacterium tuberculosis human type.

Bovine-type Mycobacterium tuberculosis: Infection can also be caused by drinking unpasteurized milk with bacteria, or its products.

Predisposing factors

Low immune function: When the human body’s immune function is low, it cannot clear the Mycobacterium tuberculosis that invades the human body, leading to infection with Mycobacterium tuberculosis.

Intestinal dysfunction: dysfunction of intestinal motility and secretion can lead to a decrease in local resistance, causing Mycobacterium tuberculosis to attack.

Infection pathway

Intestinal tuberculosis is mainly secondary to pulmonary tuberculosis, but can also enter the intestines through food.

Source of infection

Open tuberculosis patients are the main source of Mycobacterium tuberculosis.

Unpasteurized milk and its products can also transmit Mycobacterium bovis.

Routes of transmission

Respiratory tract

Respiratory transmission is the main mode of transmission of tuberculosis.

Droplets and/or sputum exhaled by a sick person through sneezing, coughing, etc. can contain a large number of Mycobacterium tuberculosis, which can be adsorbed in airborne dust after drying, thus causing transmission.

Digestive tract transmission

Less common.

Eating food contaminated with Mycobacterium tuberculosis and drinking unpasteurized, contaminated milk can cause transmission.

Other routes of transmission

Rarer than GI transmission.

These include open wounds and vertical transmission from mother to child.

Susceptible Population

People are generally susceptible, but infection does not necessarily lead to tuberculosis.

Pathogenesis

Tuberculosis

Whether or not tuberculosis develops depends on the result of the interaction between Mycobacterium tuberculosis and the human body, and the disease may develop when the following conditions are met

When the invading Mycobacterium tuberculosis is virulent and numerous.

The body is immunocompromised.

Intestinal tuberculosis

Prevalent sites

Intestinal tuberculosis occurs mainly in the ileum and may be associated with the following factors:

Since the ileocecal region is more spacious than the ileum, intestinal contents containing Mycobacterium tuberculosis tend to stay here. This in turn increases the probability of infection of the intestinal mucosa here.

Lymphatic tissue is relatively abundant in the ileocecal region and Mycobacterium tuberculosis tends to invade the lymphatic tissue.

Why symptoms occur

Since Mycobacterium tuberculosis is an intracellular infection, its immune clearance is mainly mediated by T cells.

T-cells cannot kill Mycobacterium tuberculosis intracellularly, but they can act on infected cells, causing them to rupture and release Mycobacterium tuberculosis.

T-cell-mediated cellular immunity, with macrophages as the main effector cells, produces a delayed-type hypersensitivity reaction, leading to localized chronic inflammation and corresponding symptoms.

Symptoms

Irregular abdominal pain, alternating diarrhea and constipation are common symptoms.

Typical symptoms (digestive symptoms)

Abdominal pain: pain in the right lower abdomen, which may also be located around the umbilicus. It is usually a vague or dull pain that is not severe and often occurs during or after meals. When proliferative intestinal tuberculosis is complicated by intestinal obstruction, the abdominal pain is mainly colicky.

Diarrhea and constipation: diarrhea is one of the main symptoms of ulcerative tuberculosis, and constipation can also occur; or diarrhea and constipation alternately.

Abdominal mass: the abdominal mass is often located in the right lower abdomen, moderately hard, and may be accompanied by slight pressure pain. It is mainly seen in proliferative intestinal tuberculosis.

Other symptoms (systemic symptoms)

Intestinal tuberculosis is often associated with tuberculosis toxemia and therefore the following symptoms may occur:

Low-grade fever in the afternoon.

Night sweats, a symptom in which sweating occurs during sleep and stops when you wake up.

Weakness.

Wasting and edema.

Complications

The following complications can occur with intestinal tuberculosis:

Intestinal obstruction: the main symptoms are abdominal pain, nausea and vomiting, abdominal distension and cessation of defecation.

Fistula: This manifests as an opening in the skin of the lower right abdomen through which intestinal contents may spill out. Symptoms such as redness, swelling, heat and pain may occur.

Acute intestinal perforation: less common, mainly manifested by severe abdominal pain, abdominal distension and fever.

Consultation

Department of Medicine

Gastroenterology

If you experience irregular abdominal pain, diarrhea alternating with constipation, or a lump in the lower right abdomen, it is recommended that you consult a doctor promptly.

Preparation

Consultation: Registration, Preparation of Documents, Frequently Asked Questions

Tips

Before going to the doctor, try to keep a record of the symptoms you have experienced and their duration for the doctor’s reference.

Preparation List

Symptom list

Pay particular attention to the time of onset of symptoms, special symptoms, etc.

Are there any symptoms such as abdominal pain or diarrhea?

When did these symptoms appear?

Is there any relief in between? Under what circumstances are they relieved?

Is there any afternoon low-grade fever, night sweats, or fatigue?

Has there been any recent change in weight?

What is the change in bowel movement from before?

Have you eaten unclean food or drunk unsanitary water recently?

Have you taken any medications recently?

Medical History Checklist

Any previous intestinal diseases?

Have you had any relevant examinations?

Any history of drug allergy, etc.?

Has anyone in the family experienced similar symptoms?

Checklist

Test results in the past 6 months, which can be brought to the doctor’s office.

Routine blood test, routine stool test

Tuberculin test, gamma-interferon release test

Colonoscopy, Small Bowel Scopy

Barium intestinal X-ray, abdominal CT

List of medications

Medication used in the last 3 months, if available, bring the box or package to the doctor’s office

Anti-tuberculosis drugs: isoniazid, rifampicin

Antibacterial drugs: cefuroxime, clarithromycin, amoxicillin, levofloxacin

Antidiarrheal drugs: montelukast, berberine hydrochloride

Glucocorticoids: dexamethasone, prednisone acetate

Aminosalicylic acid preparations: aspirin, mesalazine, olsalazine, salazosulfapyridine

Diagnosis

Diagnosis is based on

medical history

History of tuberculosis, including pulmonary tuberculosis.

Recent consumption of raw unpasteurized milk or its products.

History of close contact with a person with open tuberculosis.

Clinical manifestations

Symptoms

Irregular abdominal pain.

Diarrhea, or diarrhea alternating with constipation.

Afternoon low-grade fever.

Night sweats.

Weakness.

Physical Signs

A mass appears in the right lower abdomen, which may be accompanied by slight pressure.

Laboratory Tests

Blood tests

Increased erythrocyte sedimentation rate is usually seen in intestinal tuberculosis; ulcerative tuberculosis may also cause decreased red blood cell count due to bleeding.

If a blood test shows an increased erythrocyte sedimentation rate, it may help your doctor diagnose TB.

There is no need to abstain from food or water before the blood test, but you should be careful not to drink alcohol.

Stool Tests

Stool tests can be divided into two categories: routine stool tests and fecal occult blood tests.

Routine stool test can detect white blood cells and fecal occult blood test can be positive.

There is no need to fast or drink before the stool test. The specimen should be sent to the hospital in a special container and should not be mixed with urine or other impurities.

Tuberculin test

If the result of tuberculin test is strongly positive, it can be initially judged that the infection is Mycobacterium tuberculosis, which is meaningful for the diagnosis of intestinal tuberculosis.

You should rest for a while before leaving after the tuberculin test. The injection site should not be scratched or rubbed, and other medications should not be applied.

Gamma-interferon release test

Mycobacterium tuberculosis gamma-interferon release test is to reflect whether the organism is infected with Mycobacterium tuberculosis. It is more specific than the tuberculin test in diagnosing tuberculosis infection and is not affected by the BCG vaccine.

A negative test means that the body is not infected with Mycobacterium tuberculosis and a positive test means that the body is infected with Mycobacterium tuberculosis.

Precautions are the same as for the tuberculin test.

Imaging

The main imaging tests for intestinal tuberculosis are barium x-ray contrast of the small intestine and CT enterography (CTE).

CTE can show the lesion site and whether there is any change in the abdominal lymph nodes.

Metal objects, such as belts, need to be removed from the abdomen before the examination. Children need to be assisted by an adult such as a parent during the examination.

Endoscopy

The main endoscopic examinations for intestinal tuberculosis are small enteroscopy and other tests for intestinal tuberculosis that cannot be clarified by other tests.

Enteroscopy not only can directly observe the intestinal mucosa, but also can clamp the lesion tissue for pathologic examination, and the results have diagnostic value.

Precautions

Start eating semi-liquid or low-slag diet, such as milk, porridge, noodles, thin rice, etc., 1 to 3 days before the colonoscopy, avoid eating vegetables, fruits and other foods containing more fiber.

Fasting is required on the day of examination; before the examination, take oral laxatives as prescribed by the doctor for bowel cleansing until the discharge is light yellow, non-slaggy watery stool.

Before the examination, please bring the electrocardiogram, previous colonoscopy results and relevant information such as pathological diagnosis and imaging examination.

For normal colonoscopy without colonoscopic treatment, you can eat after the abdominal distension disappears about 2 hours after the examination.

Painless colonoscopy needs to be accompanied by a family member, and after the examination, you should lie down and rest, and get up and move around only after you are completely awakened, and don’t drive on the day of the examination.

Differential Diagnosis

Crohn’s disease

Similarities: both may appear abdominal pain, diarrhea and constipation alternating with changes in bowel habits and other symptoms; in addition, X-ray and endoscopy often look similar to intestinal tuberculosis.

Differences: Crohn’s disease does not have a history of extraintestinal tuberculosis; there is a tendency to remission and relapse, and the course of the disease is generally longer; although the lesions are mainly in the terminal segment of the ileum, other intestinal segments may be involved and segmental distribution; generally accompanied by fistulas or peri-rectal lesions; and the treatment of anti-tuberculosis drugs is ineffective. It can be differentiated by history inquiry and tuberculin test.

Colon cancer (right side)

Similarities: both may present with abdominal pain, change of bowel habit such as alternating diarrhea and constipation, and right lower abdominal mass.

Differences: colon cancer is mostly seen in middle-aged and old people, while intestinal tuberculosis is mostly seen in young and middle-aged people; colon cancer is usually not accompanied by characteristic manifestations of tuberculosis such as low afternoon fever and night sweats. It can be differentiated by endoscopy.

Intestinal amebiasis

Similarity: both of them can present abdominal pain, diarrhea and other symptoms.

Differences: intestinal amebiasis is usually characterized by pus, mucus and blood, while intestinal tuberculosis is not; intestinal amebiasis may be accompanied by liver abscess, which is characterized by pain in the right upper abdomen (liver area), nausea and vomiting, while intestinal tuberculosis usually does not have these symptoms. It can be differentiated by clinical manifestations, medical history and tuberculin test.

Treatment

Therapeutic objectives

Aims of treatment: Eliminate symptoms, improve general condition, promote healing of lesions and prevent complications.

Treatment principle: early treatment is emphasized for intestinal tuberculosis; early lesions of intestinal tuberculosis can be reversed by active treatment; when complications occur, surgery can be considered.

Treatment Methods

General treatment

Active intestinal tuberculosis suggests bed rest and reducing calorie consumption.

Exercise and heavy physical labor are not recommended.

Improve nutrition and increase body resistance.

Stop smoking and drinking.

Avoid excessive tension and anxiety.

Medication

Anti-tuberculosis treatment is firstly needed for intestinal tuberculosis, and the requirements are early, combined, appropriate dosage and whole course of medication. Common drugs include isoniazid, rifampicin, acetylbutylamine, pyrazinamide and streptomycin.

Isoniazid

Isoniazid can inhibit the synthesis of Mycobacterium tuberculosis and interfere with the reproduction of Mycobacterium tuberculosis, which has a strong anti-tuberculosis effect.

Isoniazid has a high safety profile.

Common adverse reactions are peripheral neuritis, liver function impairment, so take this drug should be regularly tested liver function index. Hepatic impairment and peripheral neuritis are contraindications to this drug.

Rifampicin

Rifampicin kills Mycobacterium tuberculosis by interfering with the synthesis of deoxyribonucleic acid and protein of Mycobacterium tuberculosis.

Adverse reactions are transient hepatic impairment, headache and fever.

This drug should not be used by people with hepatic impairment.

Ethambutol

Ethambutol kills Mycobacterium tuberculosis by inhibiting mycobacterial ribonucleic acid synthesis.

Adverse reactions are optic neuritis and gastrointestinal reactions.

Visual impairment is a contraindication to this drug.

Pyrazinamide

Pyrazinamide kills Mycobacterium tuberculosis by interfering with the deamidation of the enzyme in Mycobacterium tuberculosis.

Adverse reactions are hepatic impairment and arthritis.

This drug is contraindicated in people with abnormal liver function and those with gout.

Streptomycin

Streptomycin kills or inhibits the growth of Mycobacterium tuberculosis by interfering with its protein synthesis.

Adverse reactions include auditory nerve damage, fever, and drug-induced rash.

It is contraindicated in pregnant women, those with impaired hearing and those who are allergic to streptomycin.

If TB is accompanied by abdominal pain, pain relief therapy is also needed, and commonly used drugs are anticholinergics.

Symptomatic supportive treatment

When abdominal pain is severe, anticholinergic drugs are used for pain relief.

Adverse reactions include constipation, palpitations, dry mouth, dilated pupils, slurred speech, irritability, dry skin and fever, hallucinations, and convulsions.

The drug is contraindicated in patients with glaucoma and prostatic hyperplasia.

Inadequate food intake and severe diarrhea, on the symptomatic supplementation of water, electrolytes and so on.

Surgical treatment

Surgical treatment is applicable to patients with complicated intestinal obstruction and is limited to strangulated intestinal obstruction and intestinal obstruction that is ineffective after conservative treatment.

Incomplete intestinal obstruction does not require surgery, but fasting and gastrointestinal decompression are needed to correct the disturbance of water, electrolyte and acid-base balance.

Prognosis

Cure

Untreated patients usually cannot be cured on their own, irregular abdominal pain, alternating diarrhea and constipation, right lower abdominal mass, etc. seriously affect the quality of life.

TB can be cured with timely and standardized treatment. Early diagnosis, timely and rational use of anti-tuberculosis drugs, and adequate dosage and duration of treatment are the keys to cure.

Harmfulness

Impact on life

Intestinal tuberculosis may cause irregular abdominal pain, diarrhea, accompanied by low-grade fever, night sweats and other symptoms, which may seriously affect daily life.

Intestinal tuberculosis is a chronic specific infection caused by Mycobacterium tuberculosis invading the intestines, and some patients are infectious.

Complications

Intestinal tuberculosis is associated with complications such as intestinal obstruction, fistula and acute intestinal perforation.

Economic burden

As the treatment of tuberculosis is long and costly, it imposes a heavy financial burden on the patient and his/her family.

Daily

Daily management

Dietary management

Do not eat food that is too cold, too hot, greasy, spicy and stimulating.

Do not drink strong tea and coffee.

Pay attention to nutritional supplements and eat high-calorie, high-protein, high-vitamin, easy-to-digest foods, such as eggs, lean meat, fresh fruits and vegetables, soybean products.

Lifestyle management

Work and rest on a regular schedule, do not stay up late, and ensure sufficient sleep.

If surgical treatment is performed, bed rest is required as prescribed by the doctor.

Psychological management

Keep in a good mood and avoid bad emotions.

Prevention of infection

Care should be taken to avoid spreading the infection to others. Wear a mask when talking or going out.

Sputum and other secretions should be spat out in a sealed bag and burned or buried, and should not be exposed to others.

Follow-up

Importance of follow-up examinations: Regular follow-up examinations can help to detect complications in time, which is crucial to the effectiveness of the treatment.

Timing of follow-up: Follow the doctor’s instructions for regular follow-up; if irregular abdominal pain, diarrhea, accompanied by low-grade fever, night sweats and other symptoms occur in daily life, it is recommended to consult the doctor in time.

Tests to be done at follow-up: People with intestinal tuberculosis may need endoscopy and tuberculin test at follow-up.

Prevention

People not infected with Mycobacterium tuberculosis

Infants who are not infected with Mycobacterium tuberculosis are immunized with BCG vaccine.

Ventilate and disinfect the living and working places.

Exercise regularly to improve one’s resistance and immunity.

Avoid close contact with TB patients.

Do not drink raw milk and its products that are not strictly sterilized.

People infected with Mycobacterium tuberculosis

Actively treat tuberculosis, laryngeal tuberculosis and other related diseases associated with this disease.

Avoid swallowing sputum.