Question Title: invisible stones?

about a year ago i awoke with severe i mean absolute worst pain possible in my upper groin and left testicle. pain to the point of unconsiosness. the doctor figured it was a stone and sent me to have a catscan done. the picture showed a stone about 5/8 of an inch in my kidney and 3 little ones on thier way out, wich i passed without any problems (after pain killers). then a week later i was schedualed for lithotrypsy to remove the big stone and they couldnt find it.
the next week i was in for a ivp and they couldnt find it. a week later i had the horible experiance of cysoscopy and there was no stone to be found. no more problems for a year. now all of a sudden i have pain deep in my kidney, back, with shooting pain across my groin area. my questions are
where did the first stone go?
why did they not find it?
could the pain now be from the same stone or is this a new one?

Thank you for your inquiry. Renal colic often presents as pain in the flank which radiates to the groin and testicle with nausea, vomiting and occasionally fevers and chills. The pain is often intermittent, does not improve with position and is often difficult to find a comfortable position . The pain begins acutely and does not remit until the stone passes or is removed. To help make the diagnosis along with the history and physical and imaging study is usually performed including IVP/CT. The pain produced by renal calculi is often from stones being passed down the ureter. Calculi in the renal pelvis/kidney are often asymptomatic.
Most calculi are visible on these imaging studies, the exception are uric acid stones. Especially if the stones are large >4-6mm.

The pain you experienced originally, typifies passage of a ureteral stone. The larger stone you described would be difficult to pass. The size and location of the calculi determine the likelihood of spontaneous passage. The general consensus is stones under 5 mm have a probability of 90% of passing. A stone >1 cm in the renal pelvis/kidney is rarely going to be passed spontaneously. When they performed the original IVP they may have misidentified the upper tract stone especially if it did not show up on recent imaging studies. The other explanation is if the stone was a uric acid stone and was treated medically by alkalinizing the urine to dissolve the stone. The recurrent renal colic is most likely from a second calculi. The chance of forming a second stone is approximately 7%/yr. If the pain becomes unbearable , you feel nauseated and vomit, develop fever or chills you need to see a physician emergently.

Anyone who forms a stone should have a metabolic workup including stone analysis, 24 hr urine collection. To help prevent recurrent stones it is important to drink plenty of fluids especially water to increase your urine output. Strain your urine Once the metabolic workup is finished you can discuss further treatment options with your physician.

This information is provided for general medical education only. Please consult your physician for diagnostic and treatment options pertaining to your specific medical condition. More individualized care is available at the Henry Ford Hospital and its urban campuses by calling 1 800-6536568.

Sincerely,
HFHS-M.D. JS
*Keyword: Kidney calculi