A 25-year-old female presents with frequent, painful urination, lower abdominal pain, and a low-grade fever. Urinalysis shows pyuria. What is the likely diagnosis and treatment?
The patient's symptoms along with the presence of pyuria (pus in the urine) on urinalysis suggest a urinary tract infection (UTI), most likely cystitis (bladder infection). The initial treatment should include empiric antibiotic therapy, typically a short course of nitrofurantoin or trimethoprim-sulfamethoxazole, pending culture results.