Mindibun,
You are talking about a disease called IBD. It is a very rare condition that can occur in BOTH BPs and boas... in fact, in all boids, period. Boas get a lot of blame for passing it onto Balls because boas can be carriers of the disease without actually showing any symptoms, while BPs usually succomb to the disease and die very quickly.

It is a disease that can usually only be detected through testing in boas, and is characterized by RIs, stargazing, and neurological problems.

IBD is one of many reasons why strict quarantine procedures should be followed at all times with ALL snakes. It is NOT strictly a boa disease!!!