Pleghm not coming out

2 weeks ago i made a medical exam here in UAE and my xray doesnt come clear. Everything is ok (blood, urine) except for the xray. They are asking me to spit a pleghm but I cannot force it to come out since i am not sick. The doctor recommend me to drink mucolytic drug (i already consumed 2 bottles) but no result till now. I have little pleghm but the doctor said he needs more. He also recommend me to put sugar in my food, eat sweets so that pleghm will come out. I dont smoke or drink alcohol and i didnt experience any problem with my respiratory before. Please could anybody help me on how i can force my pleghm to come out or can anybody tell me what kind of illness i have. I still didnt take a second xray nor second opinion from other doctor and i only have 1 more week to give them my pleghm and finalize my medical exam.

[Sunny602]

I know that for a sputum sample they could help induce it by nebbing saline or something like that to thin your secretions out enough to bring up.Maybe you could ask your doctor about this to help give you enough of a sample. I have the same problem at times, I do nebulize a mucolytic called pulmozyme on a daily basis. (I have atypical CF). There are other drugs too called mucomyst (NAC) that can be nebbed to break down mucous. I also take guiafenesin (Mucinex) to help with my secretions. The doctors also told me to make sure that I am well hydrated, if I am dehydrated my mucous becomes very thick and difficult to bring up.
Sunny :)