Human secretin is a gastrointestinal peptide hormone that regulates secretions in the stomach, pancreas, and liver. Synthetic human secretin displays equivalent biological activity and properties as naturally occurring secretin. Acetate salt of synthetic secretin was marketed under the name ChiRhoStim. ChiRhoStim is indicated for the stimulation of pancreatic secretions, including bicarbonate, to aid in the diagnosis of pancreatic exocrine dysfunction, for the gastrin secretion to aid in the diagnosis of gastrinoma. ChiRhoStim is also used for the pancreatic secretions to facilitate the identification of the ampulla of Vater and accessory papilla during endoscopic, retrograde cholangiopancreatography (ERCP). When secretin binds to secretin receptors on pancreatic duct cells it opens cystic fibrosis transmembrane conductance regulator (CFTR) channels, leading to secretion of bicarbonate-rich-pancreatic fluid.