Is my mother's diaper causing her bladder infections?

My mom had a stroke two years ago. She wears a diaper at night. She keeps getting bladder infections. Antibiotics don't seem to help. Her only symptom was painful urination at night when she has the diaper on. Other than that, she is pain free. She has started feeling like she has to urinate right away where before she could wait. Could the diaper be causing the infection?