Yes, your mother's dry mouth, lips, and sensitive cheeks are likely connected. Diarrhea and stomach pain cause dehydration, which directly leads to dryness. Additionally, norfloxacin can sometimes cause dry mouth or mild oral sensitivity as a side effect. To help her, focus on rehydration with oral rehydration salts (ORS), water, or clear broths taken in small, frequent sips. Using a gentle, alcohol-free mouthwash or lip balm can soothe her lips and cheeks. Please ensure she completes her prescribed norfloxacin course unless advised otherwise, but consult her doctor promptly if the dryness worsens, she develops mouth sores, or she cannot keep fluids down.