During our survey on the way of detecting IBD, we found that there are several distinct defects of them: harm to the body, expensive, restricted to specific people. We are now hoping to find out a way that can make us easier to detect this kind of disease. Therefore, we are working on the development of a new diagnosis way called the Tetrathionate-Nitrate Test. We will construct an engineered probiotic which could be sent to the patient's stomach with the sugar-coated and detect the presence of these two kinds of chemicals: Tetrathionate and Nitrate, the marker of IBD. This will trigger the probiotics to produce fluorescent substances when detecting both makers. As a doctor, IBD could be diagnosed by checking if there is the fluorescent phenomenon in patients' excrement which is fast, convenient, and precise.