70 years old lady, with background history of ischaemic heart disease, hypertension, previous stroke, and rheumatoid arthritis, was admitted initially due to 3 days history of colicky right upper quadranrt abdominal pain, fever and rigor, yellow discolouration of her skin, and reduced appetite with few episodes of vomiting. On examination, patient was jaundice, with sclera icterus, and had low grade pyrexia. Blood investigation showed that patient had obstrcutive pattern of deranged liver fucntion tests (elevated ALP and GGT). U/S ABD showed gallstones in common bile duct. Patient was given antibiotic and theraeutic ERCP (Endoscopic Retrograde Cholangio-Pancreatography) was done to remove the common dile duct stone. Patient developed severe, worsening generalise abdominal pain, the next morning after the ERCP. What would be your impression or differential ??? what invesigation you should do during this stage ??