A nurse is reviewing the medical records of four clients. The nurse should identify that which of the following client findings requires follow-up care?

Warfarin is secreted in breast milk and can cause anticoagulation effects in the infant, including bleeding risk. This combination requires immediate follow-up and provider notification to assess safety and consider alternative anticoagulation. Sodium phosphate is an appropriate colonoscopy prep. Urinary frequency is an expected side effect of bumetanide (a loop diuretic). A positive Mantoux (induration) at 48 hours indicates TB exposure and requires follow-up, but it is a planned assessment finding, not an urgent unexpected complication.