"I don't know where I got hit, I fell to the ground and my body was just in shock. The doc was asking me questions and was examining me, but I'm claustrophobic, and I just really felt uncomfortable.
"I couldn't breathe and already was lying in an awkward position, but I was fine after about a minute.
"They did all the checks, I went for scans, and everything was fine.
"But in the moment it was really scary. I've never been so scared in a rugby game before. I thought there was something wrong with my whole body."
Kolisi also thanked his fans and family for the support he received after the test.
"I was getting so many messages afterwards, and obviously it was scary for my wife and everyone back home as well. But, thankfully, I am fine," he said.
Kolisi's wife Rachel said she felt scared and helpless when the incident happened.
"I don't ever wish moments like this on anyone," she wrote in an Instagram post. "When you see them go down like that, it's so hard to put into words what it feels like, but scary and helpless are probably a good place to start. Especially when your kids are very aware of what's going on too.
"I've sat next to many others that have experienced those same moments, some were fine, some had lengthy injuries and others never played the game again.
"I think we often forget these men and women put their bodies on the line for this game and things can change in a moment.
"I celebrate and thank Jesus every time Siya walks off the field safely, today a little more."
