basically there are 6 causes of gall stone formation.
Metabolic causes: cholesterol is produced from liver, which give rise to bile acids, normally bile acids and cholesterols are present in ration of 25:1 when this ratio gets below 17:1 gall stones are developed.
It may be due bile stasis
Haemolytic Anaemia also causes gall stones, because of increased bilirubin production.
Infection of E. Coli, proteus, streptococci etc are 80% causes ofgall stones
Saint triad = gall stones+ diverticulosis of colon + hiatus hernia
Intravenous pyelography X-Ray showing normal kidney, ureter, urinary bladder, as well as kidney stones, ureter stones, stones in urinary bladder, renal pelvis, you will also learn how to see position of kidney etc from this video presentation by Dr. Jaiswal Sir at Era’ s Lucknow Medical College and Hospital