This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Kidney & Ureturs, Subject name: Surgery
[{'content': 'Chronic Laxative abusage can result in the formation of which type of stone: \nSelect and explain. \nA. Xanthine, B. Cysteine, C. Ammonium urate, D. Struvite', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. (c) Ammonium urateRef NCBI pubmed, Bailey and Love 27th Edition, Page 1406Types of stones and interesting etiologies:* Primary hyperparathyroidism: Calcium oxalate stones* Renal tubular acidosis: Pure calcium phosphate stones* Cystinuria (Autosomal Recessive): Cystine stones* Ileostomies: Uric acid stone* IBD: Uric acid stone* Crohn's disease, short bowel syndromes: Calcium oxalate stones* Dietary excess of Rhubarb, spinach, tea, cocoa, chocolate and pepper: Calcium oxalate stone* Infection: Calcium magnesium ammonium phosphate stone (struvite stones)* Thiazide diuretics: Uric acid stone* Allopurinol: Xanthine stone* Laxative abusage: Ammonium urate stone", 'role': 'assistant'}]