It is best to eat fruit after eating seafood for an hour or two, because tannic acid and other ingredients in litchi will solidify crab meat protein, and the solidified substances will ferment and rot in the intestine for a long time, causing vomiting, abdominal pain, diarrhea and other reactions.
Generally speaking, eating lychee just after eating crabs is not recommended. It is best not to eat fruit immediately after eating seafood. It is recommended to eat at intervals.