The present invention relates to methods for detecting, diagnosing and/or treating ulcerative interstitial cystitis (UIC) by detecting in a urine sample from a patient the levels of each of the proteins IL-6, IL-8 and GRO [also known as CXCL 1 (chemokine C-X-C motif ligand 1]. In some embodiments, the method also includes diagnosing the patient with UIC when each of the proteins IL-6, IL-8 and GRO in the urine sample is at a different level than a statistically validated threshold for the respective proteins. In some embodiments a companion diagnostic, e.g., a cystoscopy, is used in conjunction with the protein biomarker diagnostic. In some embodiments, once UIC is diagnosed, the patient is treated for the UIC.