<prompt> A boy comes with complains of vomiting, bloated abdomen and abdominal pain. He has history of attending ice-cream eating competition last night. He also has past history of similar episodes following ingestion of milk and milk products. The likely cause -Pancreatic amylase deficiencyLactase deficiencySalivary amylase deficiencyFood poisoning  <response>: Ans. is b i.e., Lactase deficiency History of ice cream ingestion and subsequent symptoms of vomiting, bloated abdomen, are characteristic findings of lactase deficiency. Lactase deficiency ? o Lactase is a disaccharidase present on intestinal epithelium brush border. It is used to digest lactose disaccharide. Symptoms arise after ingestion offood containing lactose e.g. milk. Symptom - Diarrhoea, vomiting, bloated abdomen. o Diagnosis Presence of more than 2 percent of reducing substrate in fresh stool. Acidic stools Abnormal oral sugar tolerance test blood glucose rise of less than 20mgd1 above fasting level with a disaccharide load of 2gkg Breath H, excretion of more than 11 ppm. Enzyme assay on mucosal biopsies showing low levels of disaccharidases. o Treatment - low lactose diet. 