Thank you for your query,
Your child seems to have acute gastroenteritis
You can give sips of oral rehydrating fluids like Pedialyte or home remedies
like sips of coconut water, lemon water to maintain hydration.
For probiotics you can give curd and yogurt as they contain lactobacillus
which adds protective action of probiotic.
Continue Tylenol for fever in prescribed dose.
Monitor hydration by activity, urine output and skin turgor.
If loose motions are not controlled consult your Pediatrician
Low hemoglobin is due to iron deficiency
most commonly and child needs iron and vitamins in therapeutic dosage , so you can take treatment advise from the doctor and you can start it after loose motions subside.
In food you can give green leafy vegetables, mashed meat, and jaggery in suitable form to increase hemoglobin.
Hope I have answered your query.