What symptom is associated with renal calculi?

Severe back or side pain is indeed a classic symptom associated with renal calculi, commonly known as kidney stones. This intense pain, often referred to as renal colic, is caused by the movement of stones through the urinary tract. As stones migrate and obstruct the flow of urine, they can irritate the linings of the renal pelvis, ureters, and bladder, leading to significant discomfort that can radiate from the flank region to the lower abdomen and groin. This type of pain is typically described as sharp, sudden, and can vary in intensity.

The other symptoms listed, while they may also be present in cases of renal calculi, are not as distinctively associated with the condition. Decreased urine output can occur due to an obstruction but is not a primary symptom. Nausea and vomiting can happen as a result of pain or the body’s response to the blockage, but they are more secondary responses. Painful urination may occur if there is irritation or infection secondary to the stones, but it is not a hallmark symptom. Therefore, the severe back or side pain is the most characteristic and defining symptom of renal calculi.