A 94-year-old woman with severe dementia is referred for vaginal bleeding and a persistent foul odour from the vagina. She lives in a long-term care facility. She has been using a ring pessary for the past 15 years. Her current pessary has not been replaced in 2 years. On examination, there is moderate vaginal atrophy. After removing the pessary, which one of the following is the best next step? 

A 60-year-old woman presents with a 7-day history of bloody diarrhea and diffuse mild abdominal tenderness. Stool tests (culture, ova/parasites) are negative. Which one of the following is the best next step?

A 30-year-old woman presents to the office with her partner and reports that they are planning for her to conceive soon. They visited Mexico recently and are concerned about exposure to the Zika virus. Which one of the following is the best next step?

During an office visit, your 14-year-old patient requests a prescription for oral contraceptives. The province where you are working does not have a statutory age of consent. Which one of the following is the best next step?

An 83-year-old woman presents to your office with a 2-day history of confusion. Her past medical history is significant for lung cancer, and she is being treated with radiation. On physical examination, she is euvolemic. Her blood work reveals a serum sodium of 118 mmol/L (135–140) as compared with 134 mmol/L (8 days ago). Which one of the following will be most helpful in establishing the cause of her laboratory abnormality?