BUFFALO, N.Y. (AP) – An electronic capsule that becomes a sort of mini-laboratory when swallowed won federal approval, giving doctors another way to diagnose an uncomfortable stomach condition, its inventors said Thursday.

The wireless device, about the size of a large vitamin pill, journeys along the gastrointestinal tract collecting data and transmitting it to a receiver worn on the patient’s belt or around the neck.

When the capsule is passed from the body in a couple of days, the patient brings the cell-phone-sized receiver back to the doctor, who downloads the data to a computer. There’s no need to retrieve the capsule itself – it’s disposable.

By measuring pH, pressure and its progress through the stomach, intestines and bowel, the $500 device is designed to diagnose a condition called gastroparesis, which causes the stomach to empty slowly.

Doctors like the capsule because it can be given at the office and is reliable and noninvasive, said David Barthel, president and chief executive of SmartPill Corp., the Buffalo-based company that developed it.

Patients like it because it is more comfortable and convenient than other procedures, he said.

Currently, the most common method for diagnosing gastroparesis is a nuclear medicine test, in which a patient eats a meal laced with a small amount of radioactive material and then remains at the hospital for several hours while a scanner monitors the amount of radioactivity in the stomach.

Symptoms of gastroparesis – which affects up to 50 percent of diabetics, those suffering from Parkinson’s disease as well as others – include nausea, vomiting, abdominal pain, bloating and weight loss.

The Food and Drug Administration approved the device Tuesday following clinical trials that wrapped up in November, clearing the way for commercial sales this fall.