Does your pain get worse when eating fatty foods. If you can relieve your pain by changing your diet it might be better to wait until you get your results. If the doctors suspected gall stones that is likely what you have. Around 40 is a common age. I myself am 38. I never had anthing diagnosed by a doctor, but I have had very good reslts with my first flush.
I used Hulda's flush. Like you I have never had any other health problems. It is very easy and gentle. it is just that the Epsom Salts are vile and I plan to mix them up with some apple juice added the next time.
It is up to you. If I was you I would probably just do it. I am doing my second flush this week sometime.