Cloacal exstrophy (EC) is a severe birth defect wherein much of the abdominal organs (the bladder and intestines) are exposed. It often causes the splitting of the bladder, genitalia, and the anus. It is sometimes called OEIS complex. Cloacal exstrophy (EC) is a severe birth defect wherein much of the abdominal organs (the bladder and intestines) are exposed. It often causes the splitting of the bladder, genitalia, and the anus. It is sometimes called OEIS complex. Diagnostic tests can include ultrasound, voiding Cystourethrogram (VCUG),MRI, intravenous Pyelogram (IVP), nuclear renogram, computerized axial tomography (CAT Scan), and magnetic resonance imaging (MRI). Cloacal exstrophy is a rare birth defect, present in 1/200,000 pregnancies and 1/400,000 live births. It is caused by a defect of the ventral body wall—mesodermal migration is inhibited and folding fails.