Hi, thanks for asking in Healthcare Magic.
First and most important step is to rule out dehydration in your daughter as it is chronic (long standing) diarrhea. The signs of
severe dehydration are irritability, sunken eyes and abdomen, fever,
reduced urine output, dry skin, dry mouth and tongue. If these symptoms are present then intravenous fluids should be given. Otherwise, give ORS (oral rehydration solution) like Pedialyte to your daughter.
Watery green stools indicate Rotavirus infection.
Other likely causes are bacterial infection, amoebiasis or
giardiasis. Teething or any change in diet (like egg) or starting solid food for first time can also cause diarrhea.
Pedialyte, bland food (boiled rice cereal, oat meal, bread,mashed potatoes, boiled carrots, yogurt) breast milk and Probiotics like
lactobacillus will help to control Rotavirus infection.
Redness around anus (inflammation) is not normal. It is
diaper rash due to diarrhea. Soft paraffin ointment or olive oil will form an occlusive layer over the skin and will soothe the skin.
I hope this is useful to you.