Maximum Security is out of the Pennsylvania Derby at Parx on Sept. 21 because of colic.
A large colon nephrosplenic entrapment developed after the colt galloped on Monday, according to trainer Jason Servis.
Maximum Security Tuesday went to the Mid-Atlantic Equine Clinic in Ringoes, N.J., where the diagnosis was made by Dr. Janik Gasiorowski.
The issue is not career-threatening and Servis has no timeframe for a possible racing return.