The medications used and their use depend on your general health and the bacteria present in the urine. Cystitis caused by a bacterial infection is usually treated with antibiotics. Treatment for noninfectious cystitis depends on the underlying cause. First infection. Symptoms often improve significantly after about a day of antibiotic treatment. However, you will likely need to take antibiotics for three days to a week, depending on the severity of the infections. TESTS AND DIAGNOSIS If cystitis is suspected, the doctor first examines the person's abdomen and lower back to assess for unusual enlargement of the kidneys. or swelling of the bladder. Tests the doctor may order: Urinalysis. This is to determine if bacteria, blood or pus are present in the urine.Cystoscopy. Use to collect a small tissue sample (biopsy) for laboratory analysis. This test will probably not be necessary if this is the first time the patient has experienced signs or symptoms of cystitis. (Continued) Imaging tests. Imaging tests are usually not necessary, but in some cases, especially when no evidence of infection is found, they can be helpful. For example, an X-ray or ultrasound can help rule out other potential causes of inflammation, such as a tumor or structure.