 From these measurements, the percent retention of SeHCAT at 7 days is calculated.A 7-day SeHCAT retention value greater than 15% is considered to be normal, with values less than 15% signifying excessive bile acid loss, as found in bile acid malabsorption.With more frequent measurements, it is possible to calculate SeHCAT retention whole-body half-life; this is not routinely measured in a clinical setting.