[Expert Solution]: Darrell returns for a follow-up visit 6…

Darrell returns for a follow-up visit 6 weeks later and reports little improvement in symptoms. He states that he has been taking his medication as directed. The next best course of action is to: Increase the dose of the medication. Add a 7-day course of oral vancomycin to his regimen. Switch the medication to oral omeprazole. Referral for endoscopy and biopsy