What causes PEI?

PEI is a major consequence of a wide range of other diseases and conditions (pancreatic and non-pancreatic) including cystic fibrosis, chronic pancreatitis, pancreatic cancer and gastrointestinal surgery. It may also be an important consequence in diabetes, coeliac disease, irritable bowel syndrome or inflammatory bowel disease, including Crohn’s disease.1

PEI is therefore an extra burden for patients who are already unwell.

PEI frequently accompanies common conditions:

Emerging evidence suggests that PEI is also prevalent in:*

IBS: irritable bowel syndrome
IBD: inflammatory bowel disease
*Using faecal elastase 1 (FE-1) screening. All studies used a threshold <200 μg/g FE-1 to indicate potential PEI
**Approximately 9% of diabetes is secondary to pancreatic disease11

In addition, physiological changes, including the following, can also cause PEl:12

  • Acidic duodenal pH due to gastric hypersecretion e.g. Zollinger-Ellison syndrome or low bicarbonate secretion
  • Disruption of digestive processes due to surgery e.g. post-gastrectomy


Chronic pancreatitis is the most common cause of pancreatic exocrine insufficiency; destruction of functioning pancreatic parenchyma causes insufficient amounts of enzymes to be synthesised and secreted into the duodenum in response to meal ingestion.

Keller J & Layer P, 2005


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