Can Kidney Stones Cause Diarrhea or Digestive Symptoms?

Kidney stones do not usually directly cause diarrhea. However, severe pain, nausea, stress on the body, pain medicines, infection, or a separate digestive illness can lead to loose stools at the same time, and certain warning signs should be assessed promptly.

Can kidney stones cause diarrhea?

Kidney stones do not usually cause diarrhea directly. Most people with a kidney stone have pain in the side or back, nausea, vomiting, urinary urgency, burning during urination, or blood in the urine rather than loose stools. Still, diarrhea can happen at the same time because severe pain and nausea may affect the digestive system, or because another condition is present.

In many cases, a brief episode of loose stools without fever, worsening pain, or dehydration is not dangerous and may be unrelated to the stone. However, diarrhea should not automatically be attributed to a suspected kidney stone. A urinary infection, gastrointestinal infection, medication effect, or another abdominal condition can sometimes produce overlapping symptoms.

Medical review is especially important if diarrhea occurs with fever, chills, severe or escalating pain, repeated vomiting, difficulty passing urine, confusion, or marked weakness. These features can indicate infection, dehydration, or a blockage requiring prompt care.

Why diarrhea may occur during a kidney stone episode

A stone can cause intense cramping pain when it moves through the kidney or ureter, the tube that carries urine to the bladder. This pain activates the body’s stress response and can also stimulate nearby nerves. Some people develop nausea, sweating, abdominal discomfort, or a change in bowel habits during a painful attack.

The kidneys, urinary tract, intestines, and reproductive organs are located close together and share some nerve pathways. Because of this, pain from a stone may be felt in the abdomen, groin, or pelvis and may be mistaken for a digestive problem. Pain alone does not confirm the cause, particularly when diarrhea is prominent.

Medicines used during an episode may also contribute. Some antibiotics can cause loose stools, while certain pain medicines, supplements, or laxatives may change bowel habits. It is helpful for a clinician to know about all prescription medicines, over-the-counter products, and supplements being taken.

Occasionally, diarrhea may simply result from a separate viral stomach illness, food-related illness, irritable bowel syndrome, or inflammatory bowel condition occurring at the same time. Persistent or recurrent symptoms deserve an evaluation rather than self-diagnosis.

Symptoms that may point to a kidney stone

Kidney stone symptoms vary according to the stone’s size and where it is located. Small stones may pass with little or no discomfort. A stone that blocks urine flow or moves into the ureter is more likely to cause sudden, severe pain that comes in waves.

• Sharp pain in the side, back, lower abdomen, or groin
• Blood in the urine, which may make urine pink, red, or brown
• Burning or pain with urination
• Frequent or urgent need to urinate
• Cloudy or foul-smelling urine
• Nausea or vomiting, especially during severe pain

Diarrhea by itself is not a reliable sign of a kidney stone. If loose stools are the main symptom, a digestive cause may be more likely. Likewise, pain low on the right side of the abdomen, pain with movement, or ongoing diarrhea may need assessment for conditions affecting the bowel or appendix.

People who have previously had stones may recognize a familiar pattern, but a new episode should still be checked when symptoms are severe, different from usual, or accompanied by signs of infection. More information about stone formation and care is available in kidney stones.

Other causes of diarrhea with flank or abdominal pain

Several conditions can cause both abdominal discomfort and diarrhea. Gastroenteritis, often called a stomach bug, commonly causes loose stools, cramps, nausea, and sometimes fever. Foodborne illness can have a similar presentation, often starting after contaminated food or drink.

Urinary tract infections can cause lower abdominal pain, burning urination, urgency, and cloudy urine. When an infection affects the kidneys, fever, chills, back or side pain, nausea, and vomiting may occur. A kidney infection is different from an uncomplicated stone and needs medical assessment, particularly because an infected blocked urinary tract can become urgent.

Inflammatory bowel disease, irritable bowel syndrome, diverticulitis, appendicitis, and gynecological conditions can also create symptoms that overlap with stone pain. The location, timing, associated urinary symptoms, bowel pattern, menstrual history where relevant, and physical examination all help a clinician identify the likely cause.

For this reason, it is safer not to assume that diarrhea and kidney-area pain have one explanation. Identifying the correct cause helps avoid delayed treatment and supports appropriate symptom relief.

How a doctor evaluates the symptoms

A clinician will begin by asking when the pain and diarrhea started, where the pain is felt, whether it comes in waves, and whether there are urinary symptoms, fever, vomiting, blood in the urine, or blood in the stool. They may also ask about prior stones, recent travel, food exposures, fluid intake, medicines, and family history.

A urine test can look for blood, crystals, bacteria, and signs of infection. Blood tests may assess kidney function, inflammation, and dehydration. If a stone is suspected, imaging may be used to confirm its location and size and to determine whether urine flow is blocked.

Ultrasound is often used to evaluate the kidneys and urinary tract without radiation. A low-dose CT scan may provide more detailed information in selected cases, especially when the diagnosis remains uncertain or symptoms are significant. Stool testing is not always required, but it may be considered when diarrhea is severe, persistent, bloody, or associated with travel or infection concerns.

These steps help distinguish a kidney stone from urinary infection and digestive conditions. They also guide decisions about monitoring, pain relief, stone passage, or procedures such as kidney stone treatment when needed.

Treatment and self-care considerations

Treatment for a kidney stone depends on its size, position, composition, level of pain, and whether there is obstruction or infection. Many small stones pass naturally, supported by medical pain management and a clinician’s advice on fluid intake. A doctor may prescribe medicines that help control symptoms or, in some situations, help a ureteral stone pass.

For larger stones, persistent blockage, uncontrolled symptoms, or stones unlikely to pass, a urologist may recommend a procedure. Options may include shock wave treatment to break up suitable stones, ureteroscopy to remove or fragment a stone, or other approaches based on individual circumstances. Treatment decisions should be made after imaging and specialist review.

With diarrhea, preventing dehydration is important. Small, frequent sips of water or an oral rehydration solution may be easier to tolerate than large volumes at once. People should seek advice before substantially increasing fluid intake if they have heart failure, advanced kidney disease, or another condition that requires fluid restriction.

It is sensible to avoid relying on anti-diarrheal medicines if there is fever, blood in the stool, severe abdominal pain, or concern for infection unless a clinician advises otherwise. Keeping a note of urine changes, bowel symptoms, temperature, medications, and fluid intake can assist medical evaluation.

When to seek medical care

Urgent medical care is needed for severe pain that cannot be controlled, fever or chills with urinary pain or flank pain, repeated vomiting, inability to keep fluids down, inability to urinate, fainting, confusion, or signs of significant dehydration such as very little urine, dizziness, or marked weakness. These symptoms may indicate infection, obstruction, or dehydration that should not be managed at home.

Prompt assessment is also advisable for visible blood in the urine, persistent diarrhea lasting more than a few days, blood or black material in the stool, worsening abdominal pain, or symptoms in someone who is pregnant, immunocompromised, has one functioning kidney, or has known kidney disease.

If symptoms are mild but recurring, a primary care clinician or urologist can investigate possible stones and discuss prevention. Acibadem International’s multidisciplinary specialists and JCI-accredited hospitals evaluate and treat kidney and urinary conditions for international patients.

Even when a kidney stone is known, new digestive symptoms should be discussed with a qualified healthcare professional. A careful evaluation can provide reassurance when symptoms are benign and identify problems that require treatment.

Frequently asked questions

Can kidney stones cause diarrhea and nausea?

Kidney stones commonly cause nausea, particularly when pain is severe. Diarrhea is less typical and is not usually caused directly by the stone. It may occur because of pain, stress, medication effects, or a separate digestive illness.

Is diarrhea a sign that a kidney stone is passing?

Diarrhea is not a dependable sign that a stone is passing. Passing a stone more often causes wave-like pain, urinary urgency, burning, or blood in the urine. A clinician can confirm a stone and assess whether it is moving or blocking urine flow.

Can a kidney infection cause diarrhea?

A kidney infection more commonly causes fever, chills, flank pain, painful urination, nausea, and vomiting. Some people may also have digestive symptoms, but diarrhea can have many causes. Fever or chills together with urinary symptoms and side or back pain needs prompt medical evaluation.

What should someone drink if they have diarrhea and suspected kidney stones?

Water and oral rehydration solutions can help replace fluid losses when tolerated. Small, frequent sips may be useful if nausea is present. Anyone with fluid restrictions due to kidney, heart, or liver disease should ask a clinician for individualized advice.

When is diarrhea with kidney pain an emergency?

Emergency assessment is appropriate for severe or worsening pain, fever, chills, persistent vomiting, inability to urinate, confusion, fainting, or signs of dehydration. These symptoms can suggest an infection, urinary blockage, or another urgent abdominal condition.

How can a doctor tell whether symptoms are from a stone or the bowel?

A doctor considers the symptom pattern, physical examination, urine testing, blood tests, and imaging such as ultrasound or CT when appropriate. Urinary blood or blockage may support a stone diagnosis, while bowel symptoms and stool testing may point toward digestive causes. More than one condition can occasionally be present.

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.