Olympic champion and high hurdles world record holder Aries Merritt will have a kidney transplant next week after competing in the world championships in Beijing, the 30-year-old American said on Wednesday.

Merritt, who was told he would never run again after being diagnosed with kidney disease in 2013, set the second fastest time behind compatriot David Oliver in the heats of the 110m hurdles on Wednesday.

The disease, caused by a rare genetic disorder found predominantly in African Americans, has damaged his organ to such an extent that he will receive one of his sister's kidneys in Arizona on Sept 1.