ICD-10 Code A18.3 – Tuberculosis of intestines, peritoneum and mesenteric glands (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A18.3 – Tuberculosis of intestines, peritoneum and mesenteric glands
What it is
This code identifies tuberculosis affecting the intestines, peritoneum, and mesenteric lymph nodes. Use it when documentation states abdominal TB in these sites, usually as part of extrapulmonary tuberculosis.
Clinical signs
Clinical features vary; refer to documentation. Commonly noted findings include abdominal pain, distension, ascites, bowel symptoms, weight loss, or signs of peritoneal involvement.
When to use this code
Use A18.3 when the provider documents tuberculosis of the intestines, peritoneum, or mesenteric glands, with or without bacteriologic confirmation. It may also apply when abdominal TB is specified in these structures. If the record only says “suspected” tuberculosis, check documentation before coding.
Do not use for
Do not use this code for pulmonary tuberculosis or for nonspecific abdominal pain without documented TB. If the site of infection is different or unclear, check documentation.
Coding tip
Code the documented anatomic site exactly; abdominal tuberculosis elsewhere may require a different ICD-10-CM code.