Hemosuccus pancreaticus is a rare entity, and estimates of its rate are based on small case series. It is the least frequent cause of upper gastrointestinal bleeding (1/1500) and is most often caused by chronic pancreatitis, pancreatic pseudocysts, or pancreatic tumors. As a result, the diagnosis may easily be overlooked. The usual presentation of hemosuccus is the development of symptoms of upper or lower gastrointestinal bleeding, such as melena (or dark, black tarry stools), maroon stools, or hematochezia, which is frank rectal bleeding. The source of hemorrhage is usually not determined by standard endoscopic techniques, and the symptoms of the condition are usually grouped as a cause of obscure overt gastrointestinal hemorrhage. Over one-half of patients with hemosuccus also develop abdominal pain, usually located in the epigastrium, or uppermost part of the abdomen. The pain is described as being "crescendo-decrescendo" in nature, meaning that it increases and decreases in intensity slowly with time. This is thought to be due to transient blockage of the pancreatic duct from the source of bleeding, or from clots. If the source of the bleeding also involves obstruction of the common bile duct (such as with some tumours of the head of the pancreas), the patient may develop jaundice, or "silver stools", an uncommon finding of acholic stools mixed with blood.

The causes of hemosuccus pancreaticus can be grouped into diseases of the pancreas and diseases of the vascular structures around the pancreas. Diseases of the pancreas include acute and chronic pancreatitis, pancreatic cancer, pancreatic duct stones, ruptured aneurysms of the splenic artery, and pseudoaneurysms of the splenic artery and hepatic artery. Pseudoaneurysms are complications of pancreatitis where a pseudocyst is formed, with one wall abutting an artery, usually the splenic artery. Should the arterial wall rupture, the pseudoaneurysm will hemorrhage into the pancreatic duct.

Rarely the bleeding is not channeled into the bowel from the main pancreatic duct (or "duct of Wirsung"), but rather comes from the accessory pancreatic duct (or "duct of Santorini"). The former is termed "Wirsungorrhage" and the latter is termed "Santorinirrhage". Bleeding from the duct of Santorini can be caused by pancreas divisum, a possible congenital cause of pancreatitis.

Hemosuccus pancreaticus, also known as pseudohematobilia or Wirsungorrhage, is a rare cause of hemorrhage in the gastrointestinal tract. It is caused by a bleeding source in the pancreas, pancreatic duct, or structures adjacent to the pancreas, such as the splenic artery, that bleed into the pancreatic duct. Patients with hemosuccus may develop symptoms of gastrointestinal hemorrhage, such as blood in the stools, maroon stools, or melena. They may also develop abdominal pain. Hemosuccus pancreaticus is associated with pancreatitis, pancreatic cancer and aneurysms of the splenic artery. Angiography may be used to diagnose hemosuccus pancreaticus, where the celiac axis is injected to determine the blood vessel that is bleeding. Concomitant embolization of the end vessel may terminate the hemorrhage. Alternatively, a distal pancreatectomy may be required to stop the hemorrhage.

Cystic fibrosis, is a hereditary disease that affects the entire body, causing progressive disability and early death. It is caused by a mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The product of this gene helps create sweat, digestive juices, and mucus. The name "cystic fibrosis" refers to the characteristic 'fibrosis' (tissue scarring) and cyst formation within the pancreas, causing irreversible damage, and often resulting in painful inflammation (pancreatitis).