Barley water caused urinary/lower abdomen pain during night

Dear Tutor,

My female friend have few times experience drinking slightly concentrated barley water(barley boiled with water), caused urinary tract/lower abdomen pain, especially at night, do you have any clue about it, thanks.

Hi,
There!
I don't know why the lady has got the problems.
Maybe it's allergy?

I think traditional Chinese medicine could help the symptoms, acupuncture and herbal medicines.