Kidney Stone Pain in Stomach: How to Tell, When to Worry and How It Is Treated

Most people expect kidney stone pain in the back. So when the pain shows up in the stomach instead, they blame gas, acidity, food poisoning or even appendicitis, and lose hours (sometimes days) treating the wrong problem.

Short answer: Yes, kidney stones can cause stomach pain. As a stone moves down from the kidney into the ureter (the tube that carries urine to the bladder), pain often spreads from the side and back to the front of the abdomen, the lower belly and the groin. The clues that point to a stone rather than a stomach problem are pain that comes in waves, pain on one side, nausea, and changes in urine such as blood, burning or frequent urging. A urine test and an ultrasound or CT scan confirm it.

This guide explains why stone pain is felt in the stomach, how to tell it apart from common stomach conditions, which warning signs need urgent care, how it is diagnosed, what you can safely do for relief, and how stones are treated today.

Why Kidney Stones Cause Pain in the Stomach

The kidneys sit at the back of the abdomen, but the pain they produce rarely stays there. Three things explain why kidney stone pain in the stomach is so common.

1. Shared nerves (referred pain). The kidney, ureter, intestines and parts of the abdominal wall send pain signals through overlapping nerve pathways. The brain cannot always tell exactly where the signal started, so pain from a blocked ureter is often felt in the side of the abdomen, around the navel or in the lower belly.

2. Blockage and stretching. When a stone gets stuck, urine backs up and the kidney swells (hydronephrosis). That sudden stretching of the kidney capsule and the ureter wall is what causes the severe, cramping pain known as renal colic. Pain intensity depends on how much the stone is blocking urine flow, not on how big the stone is. A 4 mm stone stuck in the ureter can hurt far more than a 15 mm stone sitting quietly in the kidney.

3. Gut reactions. The same nerve network connects the kidney to the stomach and intestines. That is why more than half of people with classic renal colic feel nauseous or vomit, and some get bloating or a sense of fullness. These symptoms make the problem look even more like a stomach bug. Read more on why kidney stones cause vomiting.

Where You Feel the Pain Depends on Where the Stone Is

Kidney stone pain moves. As the stone travels down, the pain often travels with it.

So a stone on the right side that has reached the lower ureter can produce pain in the lower right abdomen, the classic appendicitis area. This overlap is one of the most common reasons patients reach a surgeon's desk with the wrong diagnosis. For a full body map, read where do you feel kidney stone pain and kidney stone pain location and when to seek help.

5 Key Signs Your Stomach Pain Is a Kidney Stone

No single sign proves a stone, but the more of these you have, the more likely it is.

1. The pain comes in waves. Stone pain builds to a peak over minutes, eases a little, then returns. Between the waves there is usually a dull background ache. Gas pain tends to shift around and ease after passing wind; acidity is a steady burn.

2. It is on one side. Stones usually affect one kidney at a time, so the pain sits on the left or the right, often starting in the side or back and spreading to the front and down towards the groin.

3. You cannot get comfortable. People with renal colic pace, curl up, sit, stand and change position constantly. People with appendicitis or peritonitis tend to lie very still, because movement makes it worse.

4. Your urine changes. Look for pink, red or brown urine, burning, a constant urge to pass urine, passing only small amounts, or cloudy and foul-smelling urine. Even when urine looks normal, a lab test often finds microscopic blood. Read about blood in urine.

5. Nausea and vomiting come with the pain. Vomiting alongside wave-like one-sided pain and urinary changes points strongly towards a stone rather than a simple stomach upset.

Kidney Stone or Stomach Problem? How the Common Causes Differ

Many conditions can cause abdominal pain that feels like a stone. This table shows the usual differences, but it is a guide, not a diagnosis. Several of these conditions are emergencies, so a doctor's examination and tests are the only safe way to be sure.

Two practical points. First, if you are over 60 and have your "first ever kidney stone", doctors will want to rule out an aortic problem before assuming it is a stone. Second, any woman of childbearing age with one-sided lower abdominal pain should have a pregnancy test early.

For more comparisons, read what can mimic kidney stone pain, gas pain vs gallstones and is your back pain actually a kidney stone.

Warning Signs That Need Urgent Medical Attention

Go to an emergency department the same day if stomach pain from a suspected kidney stone comes with any of the following:

• Fever, chills or shivering. A blocked kidney with infection can turn into sepsis within hours. This is the single most important red flag.
• Vomiting that stops you keeping fluids or medicines down.
• Pain that painkillers do not control.
• Very little or no urine.
• Only one working kidney, or a kidney transplant.
• Pregnancy.
• Feeling faint, confused or very weak.
• Sudden severe pain if you are over 60, especially for the first time.

When infection and blockage occur together, guidelines recommend urgent drainage of the kidney (with a stent or a tube) and antibiotics, and delaying stone removal until the infection settles. Read how do you know when a kidney stone is serious, UTI vs kidney infection and hydronephrosis causes and treatment.

How Doctors Confirm That Stomach Pain Is a Kidney Stone

The diagnostic pathway is usually quick and follows these steps.

1. History and examination. The doctor asks where the pain started, how it moved, whether it comes in waves, and about urine changes, fever and past stones. Pressing the abdomen helps separate a stone (usually little tenderness at the front) from appendicitis or gallbladder disease (clear tenderness at one point).

2. Urine test. Urine routine and microscopy look for blood and signs of infection. A urine culture is sent if infection is suspected or before any procedure.

3. Blood tests. Creatinine shows how well the kidneys are working. A blood count and CRP help detect infection. Uric acid and calcium are often checked as well.

4. Ultrasound. This is usually the first scan. It is quick, has no radiation and shows whether the kidney is swollen. Its limit is that it can miss small stones and stones in the middle of the ureter.

5. Non-contrast CT KUB. This is the most accurate test for kidney stones. It shows the exact size, position and density of the stone, which decides whether it is likely to pass and which treatment suits it best. It also picks up many of the conditions that mimic stone pain.

In pregnancy, ultrasound is used first to avoid radiation.

Read the role of ultrasound and CT in diagnosing kidney stones and what to expect during your kidney stone tests.

Short-Term Relief for Kidney Stone Stomach Pain

These measures help while you arrange medical review. They are not a substitute for it.

• Painkillers prescribed by a doctor. Anti-inflammatory painkillers (NSAIDs) are the recommended first choice for stone pain in international guidelines, because they reduce both pain and swelling in the ureter. They are not suitable for everyone, including people with reduced kidney function, stomach ulcers, certain heart conditions or pregnancy, so take them only on medical advice.
• Anti-nausea medicine, if prescribed, so you can keep fluids down.
• Heat. A hot water bag on the side or belly can ease muscle spasm. It does not move the stone.
• Steady fluids, not flooding. Drink normally to keep urine flowing. Forcing several litres at once while the ureter is blocked can increase pressure and pain.
• Do not hide a fever with painkillers. If you develop fever or chills, stop managing at home and go to hospital.

Antacids, gas medicines, beer and home remedies will not relieve stone pain. If they "work", the problem was probably not a stone. Read how to relieve kidney stone pain safely at home and how to get immediate relief from kidney stone pain.

Will the Stone Pass on Its Own?

It depends mainly on size and position.

• Stones up to about 5 mm pass on their own in most people, usually within a few weeks, with fluids and pain control. See best treatment for 5mm kidney stones.
• Stones of 5 to 10 mm in the lower ureter may be given a time-limited trial of medicine (alpha blockers such as tamsulosin) that relaxes the ureter, if there is no infection and pain is controlled.
• Stones of 10 mm or more, or any stone with infection, uncontrolled pain or a badly swollen kidney, usually need treatment. See best treatment for 10mm kidney stones.

When the stone reaches the bladder, the stomach pain often eases and is replaced by urgency and frequency. Read how long does it take to pass kidney stones, signs that a kidney stone is about to pass and non-surgical treatment options for small kidney stones.

Minimally Invasive Treatments for Kidney Stones

Open surgery for stones is now rare. The procedure chosen depends on stone size, position, hardness and the patient's health.

URSL (ureteroscopic lithotripsy). For stones stuck in the ureter, which are the ones most likely to cause stomach and groin pain. A thin telescope is passed through the natural urinary passage up to the stone, which is broken with a laser and removed. No cut on the body. Read more about URSL.

RIRS (retrograde intrarenal surgery). For stones inside the kidney, usually up to about 2 cm. A flexible scope travels through the urinary passage into the kidney and a laser breaks the stone into dust and fragments. No incision and no scar. Most patients go home the same day or the next morning. Read about RIRS.

FANS-RIRS (suction-assisted RIRS). An advanced form of RIRS that uses a flexible suction sheath to remove stone dust and fragments during the procedure while keeping pressure inside the kidney low. It is useful for larger or multiple stones. Read the FANS-RIRS guide.

ESWL (shock wave lithotripsy). Shock waves are focused on the stone from outside the body, with no instrument inserted. It suits selected kidney stones that are not too hard and not in the lower part of the kidney. Fragments then pass in the urine, which can cause a few episodes of pain, and more than one session is sometimes needed. See ESWL and when ESWL is helpful.

PCNL and Mini PCNL. For large stones, usually over 2 cm, and staghorn stones. The stone is removed through a small keyhole puncture in the back. It involves a small wound and a hospital stay of a day or two, but it clears large stone loads efficiently. Read about Mini PCNL and who is the right candidate for PCNL.

For a side-by-side comparison, read RIRS vs PCNL vs ESWL.

What Recovery Looks Like

• Hospital stay: same day or overnight for URSL and RIRS; one to two days for PCNL.
• Return to desk work: usually within two to four days after URSL or RIRS, and about a week after PCNL.
• DJ stent: a temporary soft tube is often placed after the procedure and removed after one to three weeks. Mild burning, urgency or pink urine is common while it is in place. Read about the DJ stent.
• Pain: usually much less than the stone pain that brought you in, and controlled with simple tablets.
• Red flags after the procedure: fever, inability to pass urine, or heavy bleeding with clots need urgent review.

Read more about recovery after kidney stone surgery.

After the Pain: Preventing the Next Episode

About half of people who have one stone will form another within 5 to 10 years if nothing changes. Ask for the passed or removed stone to be analysed, since the stone type decides your prevention plan, and consider a 24-hour urine test if you have had more than one stone. Read kidney stone analysis and how to avoid kidney stone recurrence.

Get Your Stomach Pain Checked

If you have wave-like, one-sided stomach pain with nausea or urine changes, do not keep treating it as gas. A urine test and a scan can settle the question within hours. Use our kidney stone checker to understand your symptoms and stone report, explore all options on the kidney stone treatment page, or book a consultation with Dr. Deepanshu Gupta, MCh Urology, who performs RIRS and FANS-RIRS daily for patients from across India and abroad.

Frequently Asked Questions

Can kidney stones cause stomach pain without back pain?

Yes. Stones in the middle or lower ureter often cause pain mainly in the side, the lower abdomen or the groin, with little or no back pain. Pain can also start in the back and then move entirely to the front as the stone travels down.

Which side of the stomach hurts with a kidney stone?

The side of the affected kidney. A right-sided stone causes right-sided abdominal pain and a left-sided stone causes left-sided pain. Stones in both kidneys at the same time are possible but less common.

How do I know if it is a kidney stone or appendicitis?

Stone pain usually comes in waves, makes you restless, and often comes with blood in the urine or urinary urgency. Appendicitis pain usually starts around the navel, settles in the lower right abdomen, gets steadily worse, and makes you want to lie still, often with fever and loss of appetite. The two can look very similar, so an examination, urine test and scan are needed to be sure.

Can kidney stones cause gas and bloating?

They can. The pain and the nerve connections between the kidney and the gut can slow the intestines, causing bloating, nausea and a feeling of fullness. Bloating alone, without wave-like one-sided pain or urine changes, is more likely a digestive issue.

Is kidney stone stomach pain worse after eating?

Not usually. Stone pain is not linked to meals. Pain that reliably starts after eating, especially fatty food in the upper right abdomen, points more towards gallstones or a stomach problem.

How long does kidney stone pain in the stomach last?

A single wave of colic lasts from a few minutes to an hour, and attacks can come and go for days or weeks until the stone passes or is removed. Pain that lasts more than a few days, keeps returning, or needs strong painkillers should be assessed for treatment.

Does stomach pain mean the stone is moving?

Often, yes. A change from back pain to front, lower abdomen or groin pain usually means the stone has moved down the ureter. When it reaches the bladder, the abdominal pain often eases and urinary urgency takes over.

Should I go to the emergency room for kidney stone stomach pain?

Go the same day if the pain comes with fever or chills, persistent vomiting, very little urine, pain that painkillers do not control, pregnancy, or if you have only one kidney. Fever with a blocked kidney is an emergency.

References

1. Patti L, Leslie SW. Acute Renal Colic. StatPearls. Treasure Island (FL): StatPearls Publishing; updated December 2024. https://www.ncbi.nlm.nih.gov/books/NBK431091/
2. European Association of Urology. EAU Guidelines on Urolithiasis: Recommendations. https://uroweb.org/guidelines/urolithiasis/chapter/guidelines