The nurse is providing dietary instructions for a client who is being discharged after passing a calcium oxalate renal stone. Which food should the nurse instruct the client to avoid?

Choice A reason: Sweet potatoes are not a food that the client should avoid after passing a calcium oxalate renal stone, because they are low in oxalate, which is a substance that can combine with calcium in the urine and form stones. The client should limit foods that are high in oxalate, such as spinach, rhubarb, beets, nuts, chocolate, tea, and wheat bran. Therefore, this choice is incorrect. Choice B reason: Spinach salad is a food that the client should avoid after passing a calcium oxalate renal stone, because it is high in oxalate, which can increase the risk of stone formation. The client should consume foods that are low in oxalate, such as rice, corn, apples, grapes, peaches, and cheese. Therefore, this choice is correct. Choice C reason: Bananas are not a food that the client should avoid after passing a calcium oxalate renal stone, because they are low in oxalate and high in potassium, which can help prevent stone formation. The client should increase the intake of fluids, calcium, and citrate, which can reduce the concentration of oxalate and calcium in the urine and inhibit stone formation. Therefore, this choice is incorrect. Choice D reason: Fish is not a food that the client should avoid after passing a calcium oxalate renal stone, because it is low in oxalate and high in protein, which can help maintain muscle mass and prevent weight loss. The client should moderate the intake of animal protein, such as meat, poultry, eggs, and dairy products, which can increase the acidity of the urine and promote stone formation. Therefore, this choice is incorrect.