Please do continue to BF. Charcoal pills are okay and so is Smecta.
I ALWAYS get diarrhoea from food poisoning episodes (BAH) so I can tell you that it's super duper safe to BF.
Just make sure you take in lots of liquids coz the frequent purging dehydrates the body and ultimately will impact your milk supply. And oh, strict hygiene rules (washing hands with soap often or every time you wanna touch your little one plus use hand disinfectant) apply to you and everyone in your house too coz it may be from a tummy bug and those spread very easily once someone catches it.