Once a kidney stone reaches your bladder, the hardest part of its journey is usually over. The bladder sits just above the urethra, the tube that carries urine out of your body, and most small stones will pass on their own within hours to a few days. Stones under 5 mm (about the width of a pencil eraser) almost always exit without help. Larger stones, or those causing significant symptoms, may need medical intervention.
Why the Bladder Is Usually the Easy Part
The ureter, the narrow tube connecting the kidney to the bladder, is the tightest bottleneck in the urinary system. If a stone made it through that passage, it can generally make it through the urethra too. The urethra is wider than the ureter in most people, especially in women, whose urethras are shorter and more flexible. Men have a longer, narrower urethra that curves around the prostate, which can occasionally slow things down, but small stones still pass without trouble in the vast majority of cases.
The main reason a stone stalls in the bladder is size. A stone that grew while sitting in the bladder (a true bladder stone, rather than one that traveled from the kidney) can become too large to exit naturally. Stones can also get stuck if the bladder doesn’t empty completely due to an enlarged prostate or other obstruction.
How to Help a Small Stone Pass Naturally
If your stone is small and your doctor has confirmed it’s in the bladder, you can take several steps to speed things along.
Drink plenty of water. Aim for about 2 liters (roughly eight to ten 8-ounce glasses) spread throughout the day. Higher fluid intake increases urine volume, which creates more flow to push the stone out. A meta-analysis from the National Kidney Foundation found that people producing 2 to 2.5 liters of urine daily were 50% less likely to develop stones in the first place, and that same volume helps flush existing ones.
Stay active. Light movement like walking encourages the stone to shift toward the urethra. Sitting still for long periods doesn’t help. You don’t need vigorous exercise, just normal daily activity.
Urinate when you feel the urge. Don’t hold it. Each time you urinate, you give the stone another chance to move. Some people find it easier to pass a stone while sitting (which relaxes the pelvic floor) rather than standing.
Manage pain. Over-the-counter anti-inflammatory medications can ease discomfort while you wait. A heating pad on your lower abdomen may also help with cramping.
Do Alpha-Blockers Help?
Your doctor may prescribe tamsulosin, a medication that relaxes smooth muscle in the urinary tract, to help the stone pass. The evidence is mixed. A large multicenter trial of over 1,100 patients found that tamsulosin produced nearly identical passage rates to placebo for stones under 5 mm (81% vs. 80%). For stones between 5 and 10 mm, though, a separate trial showed a meaningful improvement in passage rates. Current guidelines recommend tamsulosin for stones in that 5 to 10 mm range but not for smaller ones, where your body will likely do the job on its own.
When a Stone Won’t Pass on Its Own
If the stone is too large, if it’s been several days with no progress, or if you’re developing worsening symptoms, your doctor will likely recommend a procedure. Stones that formed in the bladder itself (rather than traveling from the kidney) are especially likely to need removal because they can grow quite large before causing symptoms.
Signs that you need medical help sooner rather than later include:
- Complete inability to urinate
- Severe lower abdominal pain that isn’t controlled by medication
- Fever or chills, which suggest infection
- Blood in your urine that increases rather than decreases
The inability to urinate (acute urinary retention) is a medical emergency. If a stone blocks the bladder outlet entirely, urine backs up and pressure builds, which can become life-threatening without prompt treatment.
How Bladder Stones Are Removed
The most common procedure is called a cystolitholapaxy. It’s minimally invasive and typically done as an outpatient procedure, meaning you go home the same day.
Here’s what happens: a surgeon inserts a cystoscope, a thin tube with a camera on the end, through the urethra into the bladder. The camera shows exactly where the stone is. Then, using a laser or ultrasound device threaded through the same tube, the surgeon breaks the stone into tiny fragments. Finally, the pieces are flushed out of the bladder with fluid. No incisions are needed.
For very large stones that can’t be broken up through the urethra, open surgery through a small incision in the lower abdomen is an option, though this is uncommon with modern equipment.
What Recovery Looks Like
After a cystolitholapaxy, most people experience some burning during urination and may notice blood-tinged urine for a day or two. These are normal. You may have a catheter placed temporarily if there’s swelling, but many patients don’t need one.
Most people return to normal daily activities within a few days. Heavy lifting and strenuous exercise are typically off-limits for about a week. Your doctor will likely ask you to drink extra fluids during recovery to keep urine flowing and flush out any remaining fragments.
If the stone formed because of an underlying issue, like an enlarged prostate or chronic incomplete bladder emptying, treating that root cause is important. Without addressing why the stone formed, new ones are likely to develop. Your doctor may send the stone fragments to a lab to determine their composition, which helps guide prevention strategies like dietary changes or medication.
Preventing the Next One
About half of people who pass a kidney stone will develop another within five to ten years without changes. The single most effective prevention strategy is consistent hydration. Keeping your urine dilute reduces the concentration of minerals that clump together to form stones.
Depending on your stone type, your doctor may recommend reducing sodium intake, eating less animal protein, or adjusting your calcium consumption. Contrary to a common assumption, most people with calcium stones should not avoid dietary calcium. Calcium from food actually binds to stone-forming compounds in the gut and prevents them from reaching the kidneys. It’s calcium supplements taken without meals that can raise risk.