A18.3 Tuberculosis of intestines, peritoneum and mesenteric glands

Name of the Condition

• Tuberculosis of intestines, peritoneum and mesenteric glands
• ICD Code: A18.3

Summary

Tuberculosis of intestines, peritoneum and mesenteric glands is a form of extrapulmonary tuberculosis where Mycobacterium tuberculosis infects the gastrointestinal tract, abdominal lining, or associated lymph nodes. This condition typically results from the spread of TB bacteria from a primary site, usually the lungs, via the bloodstream or lymphatic system. It can involve the intestinal wall, peritoneal cavity, or mesenteric lymph nodes, leading to localized or systemic symptoms.

Causes

Tuberculosis of intestines, peritoneum and mesenteric glands is caused by the dissemination of Mycobacterium tuberculosis from an existing infection, most commonly pulmonary tuberculosis. The bacteria may travel to the abdominal region during active disease or reactivation of latent TB. Direct ingestion of infected material is rare but possible in certain cases.

Risk Factors

• Immunocompromised states, such as HIV/AIDS or chronic immunosuppressive therapy.
• History of untreated or inadequately treated tuberculosis.
• Close contact with individuals who have active TB.
• Living in or traveling to regions with high TB prevalence.
• Underlying conditions like diabetes, malnutrition, or chronic kidney disease.

Symptoms

• Abdominal pain or cramping.
• Diarrhea or constipation.
• Weight loss or poor appetite.
• Fever, night sweats, or fatigue.
• Abdominal swelling or tenderness.
• Nausea or vomiting.
• Blood in stool (less common).

Diagnosis

Diagnosis involves a combination of clinical evaluation, imaging, and laboratory tests. A thorough patient history, including TB exposure or prior infection, is essential. Imaging studies like CT scans or ultrasound may reveal abdominal masses, fluid, or lymph node enlargement. Laboratory tests include stool analysis, blood tests for inflammation, and microbiological cultures or molecular tests (e.g., PCR) to detect Mycobacterium tuberculosis. Biopsy of affected tissue may be performed for histopathological confirmation.

Treatment Options

Treatment follows standard antitubercular therapy, typically a multi-drug regimen (e.g., isoniazid, rifampin, pyrazinamide, and ethambutol) for 6–12 months. Duration and specific drugs depend on disease severity, drug resistance, and patient factors. Supportive care, such as nutritional support or pain management, may be necessary. Surgical intervention is rare but may be required for complications like bowel obstruction or abscess drainage.

Prognosis and Follow-Up

With appropriate treatment, prognosis is generally good, though recovery may take months. Adherence to the full course of therapy is critical to prevent relapse or drug resistance. Follow-up includes monitoring for treatment response, side effects, and resolution of symptoms. Regular clinical assessments and repeat imaging or lab tests may be needed to confirm healing.

Complications

• Bowel obstruction or perforation.
• Abscess formation in the peritoneum or mesentery.
• Malabsorption or nutritional deficiencies.
• Spread of infection to other organs.
• Drug-resistant TB, if treatment is incomplete or ineffective.

Lifestyle & Prevention

• Complete the full course of prescribed TB medication.
• Maintain good nutrition and hydration.
• Practice good hand hygiene to prevent infection spread.
• Avoid close contact with individuals who have active TB until non-contagious.
• Ensure proper ventilation in living or work environments.

When to Seek Professional Help

Seek immediate medical attention if you experience:

• Severe abdominal pain or vomiting.
• Blood in stool or black, tarry stools.
• High fever, chills, or unexplained weight loss.
• Signs of dehydration (e.g., dizziness, reduced urination).
• Worsening symptoms despite treatment.

Tips for Medical Coders

Code A18.3 is used for tuberculosis involving the intestines, peritoneum, or mesenteric glands. Documentation should specify the affected site(s) and confirm the diagnosis through clinical findings, imaging, or laboratory results. Ensure the code aligns with the patient’s clinical presentation and that no more specific code (e.g., for a single organ) applies. Review the full ICD-10-CM guidelines for proper sequencing and exclusion criteria.