fistula or fissure?

my son  had anal fistula last year and after surgery it healed up really well, then not long after he was diagnosed with crohns. a couple of days ago he was complaining of his bum being really itchy and i noticed a little red lump at the opening of his anus, could this be a sign of another fistula or mayb he having a flare?  with being new to this its difficult at times as he has no other symtoms  really.  currently on 6mp, mesalazine and iron supplement.

I have been putting on sudocrem on it last couple of nights, i shower his bum everytime he has poos too but he still itches. he does have a slight discharge from his bottom anyway as i can see it on his pj,s but my husband who also has crohns also has same, he says its a mucous? i will keep an eye on it and pray that its not another fistula, will be taking him to docs to have look to be on the safe side. xx

Depends on what kind of drugs he is on also, if it is superficial then there will be no woories. Try aloe vera cream, or my mix of tea tree, vasaline, and Cold cream.

he is on 6mp and mesalazine. xx