I was prescribed Erythromycin on Monday for an infected cyst in my eye - I've not yet completed two full days of a ten day course and I am literally doubled over in agony from a stomach ache. Does anyone know anything I can do to make this better? I'm loathe to stop the AB's as my eye is awful in itself and very painful, but I can't function I'm in so much pain with my stomach - it's radiating in to my back and I feel sick too.