Hi, My Five Month Old Daughter Is Pooping Out Watery,

Hi, My five month old daughter is pooping out watery, mucus with lather. Its like soappy water. Last week her anus turned red and the frequency of motion is more than 5 tines a day. I consulted pediatrician and she gave me Ors solution and prebiotic medicine. She also suggested me to take motion test. We are unable to do due to some personal reason.After following the medicine my kid is active enough and without issues she is having her milk. Still her motion is watery with lather. But no mucus in it. As usual 4 times a day she is pooping out. Also she is very social active kid and her weight is gaining slow. It's only 5.1 kgs. How to treat her further? She is exclusively breast feed and due to playfulness she is having less sometimes. Can I go for any formula feed due to this?