Hi There, My Husband Was To Have A Series Of

Hi there, my husband was to have a series of breath tests done today looking for various food intolerances and was sent home without completing them because his hydrogen levels were "too high".
What does this mean and why would this be the case? He has been on a strict food list for the past 3 days in preparation for these tests.
Thank you for your help,
Gayle Veal

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