
    Write a function to validate whether a patient record identifier follows the hospital's standardized format, which requires different medical information categories to be joined by underscores and contain only lowercase letters. The function should return true if the identifier meets these formatting requirements and false if it does not.
    

    
import re

def text_lowercase_underscore(text):
    """
    Write a function to validate whether a patient record identifier follows the hospital's standardized format, which requires different medical information categories to be joined by underscores and contain only lowercase letters. The function should return true if the identifier meets these formatting requirements and false if it does not.
    

    """
import re

def text_lowercase_underscore(text):
    """
    Write a function to validate whether a patient record identifier follows the hospital's standardized format, which requires different medical information categories to be joined by underscores and contain only lowercase letters. The function should return true if the identifier meets these formatting requirements and false if it does not.
    

    """
    patterns = '^[a-z]+_[a-z]+$'
    if re.search(patterns, text):
        return True
    else:
        return False