Gastric bypass surgery patients may be at greater risk for kidney stones, according to a team of researchers at the Johns Hopkins University School of Medicine.
If you have had Roux-en-Y gastric bypass surgery, you may have a greater risk of developing a common — albeit painful — intestinal problem.
Doctors at the Johns Hopkins University School of Medicine found that almost 8 percent of Roux-en-Y patients in a recent study developed kidney stones. Among obese patients in a control group who did not undergo the surgery, only about 5 percent developed kidney stones.
So what is a kidney stone? It’s literally a stone – a chunk of mineral called calcium oxalate. The calcium comes from the foods you eat – milk, green vegetables, and the like. In a person with a normally-functioning digestive system, this dietary calcium gets bound together with a substance called oxalate in the intestine. Once calcium meets oxalate, the body can’t absorb it, and out it goes.
However, a person who has had a Roux-en-Y gastric bypass is missing a fairly good sized chunk of intestine, which limits the amount of fat the body can absorb – which is, after all, the whole point of the surgery. Unfortunately, this means that some of the fat they eat doesn’t get absorbed or pass through. Instead, it breaks down into a collection of fatty acids, which then combine with the dietary calcium instead of with oxalate. And when that free oxalate gets flushed into the kidneys, it links up with other calcium that’s been flushed into the renal system, and bam – kidney stones.
But there’s no need to worry over any of this. The increased risk, while significant, is still small, and it’s highly unlikely that you’ll get kidney stones when you have a Roux-en-Y procedure. And even if you do have kidney stones or some other side effect after your weight loss surgery, it’s less risky to deal with whatever those side effects might be than to stay obese. Sure, kidney stones can be painful – but obesity will kill you if left untreated.
