Commonest type of Renal stone seen in cases of UTI is:
**Core Concept**
The question is testing the relationship between urinary tract infections (UTIs) and the formation of renal stones. Specifically, it is asking about the most common type of renal stone associated with UTIs. This requires an understanding of the pathophysiology of UTIs and the factors that contribute to stone formation in the urinary tract.
**Why the Correct Answer is Right**
UTIs are often caused by bacteria such as E. coli, which can lead to an increase in urinary pH and the formation of magnesium ammonium phosphate stones, also known as struvite stones. Struvite stones are often large and can cause obstruction, leading to severe symptoms. The mechanism behind struvite stone formation involves the bacterial urease enzyme, which breaks down urea into ammonia and carbon dioxide, increasing the pH of the urine and facilitating the formation of struvite crystals.
**Why Each Wrong Option is Incorrect**
* **Option A:** Calcium oxalate stones are the most common type of renal stone overall, but they are not typically associated with UTIs. They form in acidic urine and are more common in patients with hyperoxaluria or hypercalciuria.
* **Option B:** Cystine stones are a type of stone that forms in patients with cystinuria, a rare genetic disorder. They are not typically associated with UTIs.
* **Option C:** Uric acid stones are often seen in patients with gout or those who are on a low-purine diet. They are not typically associated with UTIs.
**Clinical Pearl / High-Yield Fact**
Struvite stones are often large and can cause obstruction, leading to severe symptoms such as flank pain and hematuria. They are also more likely to cause infection and sepsis, particularly in patients with underlying medical conditions such as diabetes or immunocompromised states.
**Correct Answer: C. Struvite stones. Struvite stones are the most common type of renal stone seen in cases of UTI.**