A ureteral stent is a thin, flexible tube temporarily placed in the ureter, the duct that carries urine from the kidney to the bladder. The primary purpose of the stent is to ensure urine drainage, often after surgery for kidney stones or to bypass an obstruction. While the stent is a common and usually necessary medical device, it is considered a foreign object and can cause various side effects, including discomfort, urinary frequency, and constipation. This side effect is caused by two distinct mechanisms: the direct physical and neurological presence of the stent, and the secondary effects of necessary pain management.
The Anatomical Connection
The presence of the ureteral stent itself can contribute to constipation due to the close proximity of the urinary and gastrointestinal systems within the pelvic region. The ureters, which house the stent, lie near the colon and rectum. This shared anatomical space means that irritation in one area can easily affect the other.
The physical irritation caused by the stent, particularly the coil in the bladder, can stimulate the delicate network of nerves in the pelvis, such as the pelvic plexus. These same nerves provide sensory and motor control to the lower gastrointestinal tract, including the muscles responsible for moving stool. This phenomenon is known as visceral cross-talk, where distress signals from the urinary tract are registered by the bowel’s nervous system.
The constant low-level irritation can trigger a reflex that slows down peristalsis, the muscular contractions that push waste through the intestines. When the movement of the gut slows down, the colon absorbs too much water from the waste material. This results in hard, dry stools that are difficult to pass.
Pain Management and Bowel Changes
The most significant cause of constipation following ureteral stent placement is often the medication prescribed to manage the pain and discomfort. Opioid pain relievers are frequently given to patients, and these medications have a well-documented effect on the digestive system. Opioids bind to specific receptors located on nerve cells within the wall of the gut.
This binding slows down the rhythmic contractions of peristalsis, decreasing the speed at which waste moves through the intestines. The longer the stool remains in the colon, the more water is reabsorbed by the body, leading to stools that become excessively dry and firm. Opioids also increase the tone of the anal sphincter, making the passage of stool more difficult.
Even non-opioid medications, such as anticholinergic agents prescribed to reduce bladder spasms and urinary urgency, can contribute to the problem. These anti-spasmodic drugs also slow down gut motility, compounding the constipating effects of pain medication. Communicating openly with a physician about pain levels and medication side effects is important to ensure an appropriate and effective pain management plan.
Managing and Preventing Bowel Issues
Proactively managing and preventing constipation is a necessary step for anyone with a ureteral stent, especially while taking pain medication. Adjusting dietary habits to include a higher intake of fiber is a foundational measure to promote regularity. Foods such as fruits, vegetables, legumes, and whole grains add bulk to the stool, helping it move through the digestive tract more easily.
Adequate hydration is equally important, as water is necessary for fiber to soften the stool and prevent impaction. Patients are generally advised to drink a significant amount of fluid, often targeting three liters or 100 ounces daily, which helps both the kidneys and the bowel function properly. Increasing physical movement, even just short, gentle walks, can also help stimulate the muscles of the intestines and encourage peristalsis.
When diet and hydration are not enough, over-the-counter laxatives can be used to manage or prevent the issue, but it is important to consult a healthcare provider first. A common strategy involves combining different types of laxatives:
- Stool softeners, such as docusate, which add moisture to the stool.
- Stimulant laxatives, like senna or bisacodyl, which encourage the intestinal muscles to contract.
- Osmotic laxatives, such as polyethylene glycol, which draw water into the colon.
Patients should seek medical attention if they experience severe, persistent abdominal cramping, vomiting, or have not had a bowel movement for several days despite using preventative measures. Unresolved constipation can lead to a fecal impaction, which is a serious complication that can increase pain and may require immediate medical intervention.