Doctors took out a nearly two-pound stone from a man's body

If you have pain that isn't going away, you might end up taking a trip to the emergency room. And if cases like this one are any indication, that trip might reveal a surprisingly big problem.

According to a report published Thursday in the New England Journal of Medicine, a 64-year-old man went to the emergency room at St. Mary Medical Center Long Beach in California after he struggled peeing for three days and had pain in his left flank area (the side of his body between his ribs and hip). It turned out he came in for good reason: Doctors ended up removing a bladder stone almost as big as an ostrich egg.

The patient previously had invasive bladder cancer that required various surgical procedures, including taking out his bladder and giving him a neobladder, made from a piece of the intestine. Neobladders are specifically vulnerable to stone disease, Science Alert reports, and previous cases have proven stones can develop without many symptoms.

Doctors found two stones – including the very large one – in the ureter and neobladder. Bladder stones show up in people's bodies when they can't empty their bladders, forming hard masses of minerals, according to the Mayo Clinic. Symptoms could include severe abdominal pain or blood in the urine, though people don't always show symptoms.

The large stone weighed 1.7 pounds and was 4.7 by 3.7 by 3 inches.

Science Alert notes that this doesn't come close to the biggest bladder stone taken out of a patient (though most bladder stones won't reach this man's size, either). At a cancer clinic in Brazil, one bladder stone found inside a 62-year-old cancer patient was 7 by 5 by 3.7 inches and weighed 4.3 pounds.

In Long Beach, doctors were able to remove both stones and the patient didn't have any postoperative complications. They are monitoring him in case future stones appear.