# Gastrointestinal Tuberculosis: Clinical Presentations and Diagnostic Approaches

## TL;DR

This paper studies gastrointestinal tuberculosis in Germany, showing how it is often misdiagnosed and emphasizes the importance of histopathology and PCR for timely diagnosis.

## Contribution

The study proposes a diagnostic approach for GI TB in low-incidence settings, emphasizing early use of histopathology and PCR.

## Key findings

- GI TB was confirmed in 62.5% of suspected cases, with histopathology supporting diagnosis in all confirmed cases.
- PCR testing was positive in four of five confirmed GI TB cases, while direct microscopy was positive in only one.

## Abstract

Background: Gastrointestinal tuberculosis (GI TB) is a rare form of extrapulmonary TB that often mimics other conditions, such as Crohn’s disease (CD) or GI malignancies. Conventional diagnostics, like direct microscopy and culture, are often inconclusive or slow, delaying treatment. In Germany, a low-incidence country, GI TB is underrecognized. Rising migration has led to a resurgence of TB cases, increasing the likelihood of encountering extrapulmonary presentations. This study evaluates the performance and utility of various diagnostic tools and proposes a diagnostic approach to reduce delays and avoid unnecessary interventions. Methods: We retrospectively analyzed eight patients suspected of GI TB based on clinical presentation and testing. Two recent cases are described in detail to highlight diagnostic and therapeutic challenges. Results: GI TB was confirmed in five cases (62.5%), and all the patients presented with abdominal complaints, with the majority experiencing systemic symptoms such as weight loss or fever. Histopathology supported the diagnosis in all GI TB cases, while PCR testing was positive in four. Direct microscopy detected acid-fast bacilli in only one case. The remaining patients were diagnosed with latent genital TB, disseminated TB without GI involvement, or were ruled out clinically. Conclusions: GI TB remains a diagnostic challenge that often mimics other conditions, such as CD or malignancy. Early use of histopathology and PCR in patients with a high risk of GI TB is critical for timely diagnosis. In low-incidence settings like Germany, clinicians should maintain high suspicion in at-risk populations (e.g., migrants from areas or immunocompromised patients), especially when symptoms mimic CD or malignancy, to improve outcomes and avoid unnecessary procedures.