Sounds like this guy doesn't know how to talk to a patient, so I'll just tell you what he's doing.
The stone probably moved into the proximal ureter and obstructed, causing 'hydro' (hydronephrosis)--backpressure against the kidney. Of course, the kidney doesn't like this, and nephron ;) injury can start in hours, potentially affecting that kidney's function permanently. You're not at risk of going into kidney failure, since you only need one, but it's a semi-emergency to get it 'unobstructed'. You do that by shoving those large, painful J-stents up the ureters past the stone to relieve pressure against the kidney, allowing it to work normally. That's step 1, and the most common step 1 these guys do (I'm not a Urologist, and certainly don't think like one ;) ). Then they 'schedule' you for an outpatient lithotripsy, provided you're not sick from infection associated with the stone. Now, you don't want to litho a stone jammed in the ureter as that would rupture the ureter, most likely. You can't go up and get it with a basket (basket retrieval), because it's probably too large to pull out. What he MAY be thinking about doing is a ureteroscopy, to push the stone back up into the renal pelvis so he can litho it. The stent just allows urine to flow, but really doesn't have much to do with the stone itself.
So here's what you can expect: He'll litho this thing, which will turn it into 'smaller' pieces that you can pass. Then he'll most likely have you come back in a week or so to remove the stent and see whether stone fragments remain.
That's the end of it, provided you see a nephrologist . If you don't, you'll be sorry, and at risk of another stone. In the MEANTIME, here's some general advice for anyone out there with calcium stones:
1) Take in at least 2L of fluid, including drinking at night
2) Limit soda pop....best off if NONE. Phosphoric acid increases calcium excretion
3) NO grapefruit or grapefruit juice
4) Vitamin Budweiser--a beer a day reduces stone formation by 40%
5) Low'ish' protein diet--low animal protein, higher vegetable based protein
6) Low SODIUM diet. Calcium follows sodium. Nothing in a can, pre-prepared foods (like TV dinners or 'healthy choice'), etc. A complete list of things salty can probably be found at NKF.org.
7) DO NOT restrict your calcium intake
8) You may need to take Uro-Cit K, Bicitra, Thiazide or something else to help as well, depending on how you do.
Let me know.