The term intestinal pseudo-obstruction, is applied to a group of clinical disorders in which there are obstructive symptoms, in the absence of a mechanical agent, secondary to a disorder of intestinal motility. In this report, we show manometric studies done in four patients, with acute intestinal pseudo-obstructions, secondary to von Recklinghausen's neurofibromatosis (VRNF), in two patients, and in one patient with Duchenne's muscular dystrophy (DMD) and in another with Werdnig-Hoffmann's disease (WHD). We studied 24 hours antroduodenal motility, specially during phase 3 of the migratory motor complex (CMM), which showed a neuropathic disorder in one case of von Recklinghausen's disease and a myopathic disorder in patients with Duchenne's muscular dystrophy and Werdnig-Hoffmann's disease. We analysed results and conclusions and specially the kinetic action of erythromycin.