What is renal colic?
Renal colic is an acute pain syndrome caused by sudden obstruction of the urinary tract, usually by a stone (urinary lithiasis). The obstruction prevents the flow of urine, which causes a rapid increase in pressure in the urinary tract upstream of the obstacle, generating intense pain.
Renal colic is one of the most frequent urological emergencies. It affects approximately 1 in 10 people during their lifetime, with a peak incidence between 30 and 60 years of age.
Symptoms of renal colic
The pain of renal colic is characteristic:
- Sudden onset, often at night or after a period of dehydration.
- Lumbar location, on one side, radiating towards the lower abdomen, the groin, and the genital organs.
- Very intense, paroxysmal, evolving in waves.
- No relieving position: the patient cannot find a comfortable position and is constantly agitated.
Other symptoms may be associated:
- Nausea, vomiting.
- Frequent urge to urinate.
- Burning when urinating.
- Blood in the urine (hematuria), sometimes visible to the naked eye.
The presence of fever is a sign of severity that requires emergency consultation: it suggests an infection of the obstructed urinary tract, which constitutes an absolute medical emergency.
Diagnosis
The diagnosis of renal colic is suspected based on the typical clinical picture. It is confirmed by imaging tests:
- Non-injected abdomino-pelvic CT scan: the reference test, which visualizes the stone, its size, and its location, as well as any complications (urinary tract dilatation).
- Renal-vesical ultrasound: useful in pregnant women or for follow-up.
A blood test (assessing renal function and looking for signs of infection) and a urinary analysis are also performed.
Treatment of renal colic
Emergency treatment
The immediate management of renal colic relies on:
- Analgesics: anti-inflammatories (in the absence of contraindications) and analgesics, sometimes opiates in case of intense pain.
- Antispasmodics.
- Restriction of hydration during the acute phase (paradoxically, abundant drinking can increase the pain).
Most stones smaller than 5 mm pass spontaneously into the urine.
Specialized urological treatment
When the stone does not pass spontaneously, when the pain is uncontrolled, in case of large stone size, infection or impaired renal function, urological treatment is necessary:
- Drainage of the urinary tract by JJ stent placement or percutaneous nephrostomy in emergency, in case of associated infection.
- Treatment of the stone: extracorporeal shock wave lithotripsy, flexible ureteroscopy with Holmium laser, or percutaneous nephrolithotomy depending on the size and location of the stone.
Prevention of recurrence
After an episode of renal colic, the recurrence rate is high (approximately 50% at 5 years) in the absence of preventive measures. Prevention is based on:
- Abundant hydration: at least 2 liters of water per day, evenly distributed throughout the day.
- Adapted diet: reduction of salt and animal protein intake, moderation of foods rich in oxalates.
- Morphoconstitutional analysis of the stone (when one is recovered), to determine its composition and adapt prevention.
- Specialized metabolic assessment in case of recurrence or family history.
Dr Adam Vardi, urological surgeon, manages renal colic and urinary stones in Paris and Neuilly-sur-Seine, and is co-founder of the team Urgence Calcul Paris.