People who swallow foreign things tend to make it a habit, a study said.

Steven Moss, a gastroenterologist at the Rhode Island Hospital found that there were many people who intentionally swallowed objects, a trend that is little recognised among medical professionals

"Intentional, rather than accidental, swallowing is a poorly recognized and underappreciated problem," Moss said in a prepared statement.

Moss has help recover batteries, blades and even bed springs from patients stomachs. According to the study being published in the Clinical Gastroenterology and Hepatology, the doctors analyzed patients at the hospital where Moss works.

The hospital found they removed foreign objects from 33 people, who contributed to 305 adult cases of swallowing foreign objects. In one person, doctors removed 67 objects over a eight year period.

The reasons for foreign body ingestion vary," Colin Harrington, a psychiatrist at Rhode Island Hospital and co-author on the new study, said in a prepared statement. "It is one of many forms of self-injurious behavior." Some 79 percent of patients had been diagnosed with at least one psychiatric disorder (outside of their swallowing behavior).

"Foreign body ingestion is poorly understood, difficult to treat, and consumes considerable physician time and hospital resources," Moss said. "Attention should be focused on investigating how to avoid these preventable and costly episodes."

Most of the patients were covered under medicare or Medicaid. It cost an average of $ 45,400 to treat each patient at the hospital.