He started having stomach pain in the child recently, it hurts, redden…

He started having stomach pain in the child recently, it hurts, reddens, cries and all this happens at night. My diet hasn't changed, I drink chamomile milk tea for two weeks now, before that I drank with my home. Parents say it might be from him. I give him nettle water, Eспумизан, HiLac, BioGaia, do massage. Could it be from the chamomile milk?