Intravesical therapy for bladder cancer causing disseminated tuberculosis and perforated viscus: a case report

The ileocecal area and peritoneum are frequently affected by abdominal TB, which is uncommon (1%-3%) and usually manifests as vague symptoms that resemble malignancies. A 6-9 months of antituberculous medication is the standard course of treatment; surgery is saved for complications like obstruction or perforation. We present a case of an 81-year-old man who had recurrent bladder cancer and had previously intravesical Bacillus Calmette-Guérin (BCG) treatment. He developed diarrhea, vomiting, and a small intestinal perforation in 2025, which were originally suspected to be signs of metastatic dissemination. Necrotizing granulomatous inflammation was identified during ileocecal resection, and testing verified disseminated tuberculosis, which is most compatible with systemic BCG infection.