8 month old baby diarrhoea

Has anyone had experiences with their baby having diarrhoea? My 8 mth old baby is having it now and it caused a very big abrasion in between her bum cheeks. She will cry when we try to clean her up. I feel so bad for her. What can i do to make the diarrhoea go away. Just changed a diaper and another one came. 😓😓