Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a large hiatal hernia containing a major portion of the stomach . In comparison to the prior study , there is increased distension of the stomach , raising concern for gastric outlet obstruction . The lungs are clear . Bilateral small pleural effusions with bibasal atelectasis is noted . No pneumothorax or pulmonary edema is detected .
    OUTPUT:
    
Large hiatal hernia , interval increase in distension of the stomach , raising concern for possible obstruction . Please correlate with clinical findings for the signs of obstruction .