A ureteral stent is a thin, flexible tube placed inside the ureter, the narrow passage that carries urine from your kidney down to your bladder. It holds the ureter open so urine can flow freely when something is blocking or narrowing that path. Stents are one of the most common tools urologists use, and if you’ve been told you need one, understanding what to expect can make the experience far less stressful.
Why Stents Are Placed
The core job of a ureteral stent is to reestablish or maintain the normal flow of urine from kidney to bladder. There are three broad reasons a doctor will recommend one.
The most common reason is obstruction. A kidney stone lodged in the ureter can block urine from draining, causing intense pain and potentially damaging the kidney. A stent bypasses the blockage, letting urine flow around the stone until it can be treated. Obstruction can also come from a tumor pressing on the ureter or from a condition called retroperitoneal fibrosis, where scar-like tissue forms behind the abdomen and squeezes the ureter shut. Left untreated, any of these obstructions can lead to infection, loss of kidney function, or kidney failure.
Stents are also placed after surgery on or near the ureter. If a surgeon repairs a narrowed section of the ureter, removes a stone, or operates on nearby pelvic organs, a stent acts as an internal splint. It keeps the ureter open while the tissue heals and prevents swelling from sealing it off during recovery.
The third reason is identification. During complex pelvic surgeries, a stent makes the ureter easier to locate and avoid, reducing the risk of accidental injury to it.
What the Stent Looks Like
A ureteral stent is typically 20 to 30 centimeters long, roughly the width of a piece of spaghetti. Both ends curl into a small “J” shape, which is why it’s often called a double-J or DJ stent. One curl sits inside the kidney, and the other curl sits inside the bladder. Those curled ends anchor the stent in place so it doesn’t migrate up or down. Most stents are made of polyurethane or silicone and are designed to stay in the body for weeks to a few months.
How It’s Inserted
Stent placement usually happens during a short procedure under sedation or general anesthesia. The doctor passes a thin camera called a cystoscope through the urethra and into the bladder, then threads a guidewire up into the ureter and slides the stent over it. No external incision is needed. The whole process often takes 15 to 30 minutes.
In some cases, the doctor attaches a thin string to the bladder end of the stent. This string hangs outside the body through the urethra and allows the stent to be pulled out at home or in a quick office visit without another procedure. When there’s no string, removal requires a brief cystoscopy, similar to the insertion.
If a stent can’t be placed from below (for example, if the obstruction is too severe to pass a wire through), the alternative is a nephrostomy tube. This is a drainage tube inserted through the skin of the back directly into the kidney. It works well but requires an external bag, so doctors prefer a stent whenever one can be placed successfully.
What It Feels Like to Have One
Most people notice the stent. The coiled end sitting in the bladder can irritate the bladder wall, causing a frequent or urgent need to urinate. Some people feel a dull ache in the kidney area, especially when urinating, because urine can briefly reflux up the stent toward the kidney. You may also see small amounts of blood in your urine, particularly after physical activity. These symptoms range from mildly annoying to quite uncomfortable depending on the person, the stent’s size, and its position.
Pain or discomfort tends to be worst in the first few days and often improves as your body adjusts. Your doctor may prescribe medication to relax the bladder and reduce that constant urge to go. Drinking plenty of water helps flush the system and can dilute the urine enough to reduce burning.
Activity and Recovery
After placement, you should avoid strenuous activity for at least a few days. That includes lifting anything heavier than about 10 pounds, roughly the weight of a gallon of water. Walking and light daily tasks are generally fine. Most people return to work within a day or two if their job isn’t physically demanding, though the bladder symptoms may still be noticeable.
Staying well hydrated is one of the most useful things you can do while a stent is in place. Drinking plenty of water supports kidney and bladder function, helps prevent infection, and can reduce the irritation that concentrated urine causes against the stent.
How Long Stents Stay In
Most ureteral stents are temporary. The exact timeline depends on why it was placed. A stent put in to help pass a kidney stone might stay for one to two weeks. One placed after ureteral surgery may remain for four to six weeks while the tissue heals. Stents used for long-term management of a tumor-related blockage may need to be exchanged on a regular schedule, typically every three to six months.
Timing matters because the longer a stent stays in, the higher the risk of encrustation, a buildup of mineral deposits on the stent’s surface. Research shows that encrustation occurs in roughly 9% of stents removed before six weeks, jumps to nearly 48% for stents left in six to 12 weeks, and exceeds 76% beyond that point. A heavily encrusted stent can be difficult to remove and may require additional procedures to break up the deposits. Most experts consider an indwelling time of two to four months reasonably safe, but shorter is better when the clinical situation allows it.
Factors That Increase Complications
Several things raise the risk of encrustation and other stent-related problems. Urinary tract infections are a major one: certain bacteria produce enzymes that raise the pH of urine, causing calcium and magnesium to crystallize onto the stent surface. A history of kidney stones, abnormally high levels of calcium or uric acid in the urine, and chronic dehydration all accelerate the process.
Patients undergoing chemotherapy face elevated risk as well. Chemotherapy can increase uric acid levels in the urine, and the combination of dehydration, recurrent infections, and frequent stent exchanges creates a compounding effect. If you have any of these risk factors, your doctor will likely schedule closer follow-up and may recommend earlier stent removal or exchange.
Stent Removal
If your stent has a string, removal is straightforward. You or your doctor gently pulls the string, and the stent slides out through the urethra. This takes only a few seconds and is uncomfortable but brief. Without a string, the doctor performs a quick cystoscopy in the office, using a small grasping tool to grab the stent’s curled end in the bladder and pull it out. Sedation is not always necessary for office removal, though some practices offer it.
After removal, you may feel some burning with urination and see a small amount of blood for a day or two. These symptoms resolve quickly. Most people feel noticeably better within 24 to 48 hours once the source of bladder irritation is gone.
Stent Materials and Design
Standard stents are made from polyurethane or silicone. Silicone stents tend to resist mineral buildup better than polyurethane, which can matter for patients who need a stent for an extended period. Some stents have special coatings designed to reduce friction and bacterial adhesion.
Biodegradable stents, which would dissolve on their own and eliminate the need for a removal procedure, are in active development but are not yet widely available. Manufacturing challenges and the need for consistent degradation rates that match individual patient needs have kept them in the experimental stage. For now, all standard ureteral stents require a planned removal or exchange.