**Core Concept**
Spontaneous bacterial peritonitis (SBP) is a serious complication in patients with cirrhosis and ascites, characterized by bacterial infection of ascitic fluid without an apparent source. Prophylaxis against SBP is essential to prevent morbidity and mortality in these patients.

**Why the Correct Answer is Right**
Patients with a prior history of SBP are at increased risk of recurrence, and prophylaxis is indicated to prevent another episode. The recommended prophylactic regimen typically involves daily administration of antibiotics such as norfloxacin or ciprofloxacin. This approach is based on the understanding that patients who have previously developed SBP have an increased bacterial load in their ascitic fluid, making them more susceptible to recurrent infections.

**Why Each Wrong Option is Incorrect**
**Option A:** Patients with high protein ascites do not necessarily require prophylaxis against SBP. The presence of high protein in ascitic fluid is more indicative of a transudative process, which is less likely to be associated with SBP.

**Option C:** Serum creatinine 1 mg/dl is not a specific indicator for SBP prophylaxis. While renal impairment may be a marker of advanced liver disease, it does not directly correlate with the risk of SBP.

**Option D:** Child-Pugh score < 8 does not necessarily exclude the need for SBP prophylaxis. The Child-Pugh score is a prognostic tool used to assess the severity of liver disease, but it does not directly predict the risk of SBP.

**Clinical Pearl / High-Yield Fact**
A prior history of SBP is the strongest predictor of recurrence, and clinicians should consider prophylaxis in patients with a history of SBP to prevent recurrent episodes and associated morbidity.

**Correct Answer:**
✓ Correct Answer: B. Prior history of SBP