First of all if you have tuberculosis of any organ, the standard regimen for first instance, ruling out drug resistance is usually 6months. When we consider organ affected is other than lungs, the treatment is individualised and can extend up to 18 months as per the improvement and bacterial load. But intermittent tests and clinical improvement is monitored to tailor the duration of treatment.

Most guidelines recommend 6 months treatment for tuberculosis. Duration of treatment for extrapulmonary tuberculosis varies from 6 to 18 months that is individualised based on clinical response. The increment in duration for tuberculosis treatment is to prevent relapse. It's not essential that if you develop second time tuberculosis it is MDR, it may be drug sensitive also. The prevalence of MDR in retreatment TB cases is upto 20%.