Colonic medication bezoar from extended-release nifedipine and procainamide.

We report an unusual case of a primary colonic bezoar composed of extended-release formulations of nifedipine and procainamide. Although these bezoars are rare, the increasingly frequent application of extended-release delivery systems to other commonly prescribed medications may increase the incidence of such bezoars in vulnerable patients. Clinicians should be aware of this potential problem when prescribing these medications, and have a high index of suspicion when painful or refractory constipation occurs.