Necrosis localization and fecal pancreatic elastase-I levels. Fecal pancreatic elastase-I (FPE-1) level was lower in head and near total necrosis of the pancreas than body or tail necrosis (aP < 0.05). FPE–1 levels as follows; 189.18 ± 82.7, 324.86 ± 194, 258.06 ± 134.63 and 181.12 ± 134.25 μg/g stool in head, body, tail and near total necrosis groups, respectively.