Farah recovered from a painful fall in the 28th minute of the race to finish second to Kenya's Geoffrey Mutai, but then passed out in the finishing area before being taken away in a wheelchair.
"I do remember sort of passing out," said Farah at a post-race press conference. "I tried so hard in the race, taking a fall and then going through. But I'm all right. It's fine. It's not a big deal."
The 30-year-old was in the leading pack of eight athletes when he was sent crashing to the tarmac after seemingly being accidentally tripped from behind. He quickly got back to his feet and resumed running, but Mutai took full advantage of the incident to accelerate and pull clear with compatriot Stephen Sambu.
"I would have done exactly the same thing if I was him in the race," said Farah, who is preparing to run his first full marathon in London next month.
Mutai's countryman Stephen Sambu finished third to round off a good day for Kenya, with their compatriot Sally Kipyego winning the women's event.