My sister suffer from vomting every times she eat her food don't stay down 10 mintues but she don't loose weigth she gain weight that been going on for 6 months she even had her gall bladder taken out.

Sorry? I can't decipher your post.

Try again.

Is she "causing" this, but in either case, she needs to see a doctor, this is not normal. Plus of course if she is gaining weight, she is not getting sick every time she eats.

Does your sister suffer from Bulemia? Many bulemic girls eat as they wish but cause themselves to throw it up.

One way bulemia is different from anorexia is that a bulemic person does indeed gain or maintain weight, they do not lose it.