Noxious input to the spinal cord is known to produce central sensitization, which consists of allodynia , exaggeration of pain, and punctuate hyperalgesia , extreme sensitivity to pain. Two types of mechanical hyperalgesia can occur: 1) touch that is normally painless in the uninjured surroundings of a cut or tear can trigger painful sensations (touch-evoked hyperalgesia), and 2) a slightly painful pin prick stimulation is perceived as more painful around a focused area of inflammation (punctuate hyperalgesia). Touch-evoked hyperalgesia requires continuous firing of primary afferent nociceptors, and punctuate hyperalgesia does not require continuous firing which means it can persist for hours after a trauma and can be stronger than normally experienced. In addition, it was found that patients with neuropathic pain, histamine ionophoresis resulted in a sensation of burning pain rather than itch, which would be induced in normal healthy patients. This shows that there is spinal hypersensitivity to C-fiber input in chronic pain. 
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.