Sweet potato intolerance?

Gave Kiefer some pureed orange sweet potato for lunch yesterday. About half a cube of it. He quite like it and finished all of it. The rest of the day went as normal, he had his milk and had 2 tbsp (dry) of rice cereal for dinner at 530pm. 

Woke up at 530am to feed him his morning milk. He was a little fussy after finishing his milk and could not settle to sleep. I thought he wanted to nurse more and tried to latch him on again. But he vomited a huge amount of milk out instead. Wet our bed and had to pull the bed spread up. I thought he was dry and thus left him on his own bed but he didn't get back to sleep. Hubb got up to check on him and realised that he was all wet. He must have regurgitated again I think. So now I had to strip his bed and wash the mattress! Then he did a poop and Hubb cleaned that up. And 2 major burps (more like belches). And then I thought it might have been the sweet potato cos Kiefer was already a gassy baby and sweet potatoes can cause gas too. Came online to google on the topic for about 10min, went back in and found that he had pooped again! The poop was soft and slightly darker (I think it's just the solids he's been eating) than usual, but not watery.  

So now I'm not too sure if it was the sweet potato that caused the gassiness or that he didn't drink his milk properly. 

He just belched again!