Coffee can give you a bit of an upset stomach (5)

I believe the answer is:

mocha

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'coffee' is the definition.
(type of coffee drink)

I cannot understand how the rest of the clue works.

(Other definitions for mocha that I've seen before include "Strong dark coffee" , "Leather" , "Dark brown" , "Fine-quality coffee" , "Kid" .)

I've seen this clue in the Evening Standard.

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