Excess stomach acid misdiagnosed

Dear Dr. Roach: For more than three years, I lived with never-ending diarrhea. My doctor diagnosed me with irritable bowel syndrome. Once, I got very dehydrated and passed out after taking a shower. I was admitted to the hospital. An evaluation at that time showed a tumor on my pancreas and another on my duodenum. My blood gastrin level was 600.

After the tumors were removed (they were benign), the level was 13. When I came home, I was free from diarrhea. I have had CT scans and blood tests, all fine. Has this happened to others? — C.D.

A gastrinoma is a tumor that produces the hormone gastrin, which has the physiological role of stimulating stomach acid secretion. These can be found in the pancreas or duodenum, and having multiple tumors is not uncommon.

Most people with gastrinproducing tumors have stomach ulcers due to the high amount of stomach acid. More than 90% have stomach pain. The high acid also prevents pancreatic enzymes from working and prevents the intestine from absorbing salt and water properly. This leads to diarrhea in 70% or so of people. The combination of diarrhea and abdominal pain can look like irritable bowel syndrome. This is a rare disease, with one person per million diagnosed annually.

Although they may appear “benign” on pathology, they still have the potential to spread. Because gastrinomas are associated with other tumors as part of the “multiple endocrine neoplasia 1 syndrome,” a look for parathyroid tumors is appropriate as well.

It’s important to recognize that the diagnosis of irritable bowel syndrome is one of exclusion. This means that it is necessary to exclude other conditions before making the diagnosis. This does not mean everyone with IBS needs an evaluation for gastrinoma.