Greetings.
Stones which are less than 4 mm pass spontaneously and stone bigger than 8 mm need some kind of procedure. Stones between the size of 5-8 mm are called as border line stones and need what we term as medical expulsion therapy. Active medical expulsive therapy (MET) constitute of the following;
1) Non steroidal anti-inflammatory analgesics (NSAIDs); they have ureteral-relaxing effects.
2) The calcium channel blocker like nifedipine works in conjunction and relaxes ureteral smooth muscle and enhances stone passage.
3) The alpha-blockers, such as terazosin, and the alpha-1 selective blockers, like tamsulosin, also have the same mechanism of action and relax musculature of the ureter and lower urinary tract, facilitating passage of ureteral stones.
If these measures fail, ESWL may be resorted. Both of these agents, calcium channel blockers and alpha-blockers also appear to improve the results of extracorporeal shock-wave lithotripsy (ESWL). In ESWL the stone is fragmented in to the small pieces, so the stone fragments resulting from treatment appear to clear the system more effectively, by the ureteral relaxing effect of these medications.
Hope this helps you.
All these measures are almost painless procedures and you should not worry about them or loose sleep over them.
Please feel free for your follow up questions.
Dr. Arun
Doctor (MD)
MBBS, MS (General Surgery), Post-doctoral Fellowship in Sports Medicine