<prompt> A 10 year old boy consumes stain remover. He presented with coffee-coloured vomiting and restlessness. Most likely diagnosis: September 2012Oxalic acidDiluted HC1KeroseneCarbolic acid  <response>: Ans. A i.e. Oxalic acid The vomit in oxalic acid poisoning has a coffee ground appearance because the oxalic acid badly corrodes the stomach walls. There may be bloody vomiting for the same reason. 