Zenker’s diverticulum may not cause symptoms unless a pouch grows so large that you have trouble swallowing food. Typically, pouches are a few centimeters in size. The most common symptom is dysphagia (difficulty swallowing). Other symptoms may include: Hoarseness (dysphonia). Bad breath (halitosis). Regurgitating swallowed food. Aspiration pneumonia. Feeling there’s phlegm in your throat. Unintended weight loss because you have trouble swallowing food.