This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
[{'content': 'A boy comes with complains of vomiting, bloated abdomen and abdominal pain. He has a history of attending ice–cream eating competition last night. Ile also has a past history of similar episodes following ingestion of milk and milk products. The likely cause – \nSelect and explain. \nA. Pancreatic amylase deficiency, B. Lactase deficiency, C. Salivary amylase deficiency, D. Food poisoning', 'role': 'user'}, {'content': 'Answer: B \nExplanation: History of ice cream ingestion and subsequent symptoms of vomiting, bloated abdomen, are characteristic findings of lactase deficiency.\n\nLactase deficiency -\n\n\nLactase is a disaccharidase present on intestinal epithelium (brush border)*. It is used to digest lactose (disaccharide).\nSymptoms arise after ingestion of food containing lactose (e.g. milk).\nSymptom - Diarrhoea, vomiting, bloated abdomen.\n\nDiagnosis\n\nPresence of more than 1/2\xa0percent of reducing substrate in the fresh stool.\n\nAcidic stools\n\nAbnormal oral sugar tolerance test* (blood glucose rise of less than 20mg/d1 above fasting level with a disaccharide load of 2g/kg)\nBreath H2 excretion of more than 11 ppm*.\nEnzyme assay on mucosal biopsies showing low levels of disaccharidases.\n\nTreatment -\n\nlow lactose diet.', 'role': 'assistant'}]