Straws>?????
I don't know the reason. Who told you not to use one, your doctor? Perhaps you can ask him the reason at your next appointment?
Please note: I AM NOT A DOCTOR. If you want medical advice, talk to your doctor. Whatever I post, there is probably some surgeon or other health care provider somewhere that disagrees with me. If you want to know what your surgeon thinks, then ask him or her. Check out my blog.