First of all i dont understand what you mean by stone in stomach. Is it gall stones? Kidney
stones? Anyway, if you are having continuous fever for 20 days, i would suggest u get a chest X-ray, sputum culture
for acid fast bacilli and check for any swellings you might have in your body. It could be due to tuberculosis
. If you have significant weight loss
then the suspicion level still goes up.
Hope you get well soon