These studies suggest that the internal sphincter closes by rhythmical contractions and that at rest it is in dynamic balance with low amplitude rectal contraction waves, these waves being associated with small falls in internal sphincter pressure and loss of rhythmical activity. The underlying response of the internal sphincter to rectal distention (Fig. 6) is one of contraction with increased base line pressure and amplitude of rhythmical waves. This is modified by the presence of a rectal contraction wave which results in a relaxation of the internal sphincter, the rapid fall in pressure probably being aided by the pubo analis fibers of the pubo coccygeus. In Hirschsprung's disease the pattern is unmodified. At rest there is continuous rhythmical activity, low amplitude rectal waves being accompanied by an increase in amplitude of these waves. The resting pressures, though raised, are not markedly so. With rectal distention no fall in pressure occurs below the resting level as occurs in the normal. Rhythmical activity persists and, providing the stimulus is sufficient, a rise in base line pressure and amplitude of rhythmical wave occurs. This forms the basis for a physiological test for Hirschsprung's disease. These studies suggest that the internal sphincter closes by rhythmical contractions and that at rest it is in dynamic balance with low amplitude rectal contraction waves, these waves being associated with small falls in internal sphincter pressure and loss of rhythmical activity. The underlying response of the internal sphincter to rectal distention (Fig. 6) is one of contraction with increased base line pressure and amplitude of rhythmical waves. This is modified by the presence of a rectal contraction wave which results in a relaxation of the internal sphincter, the rapid fall in pressure probably being aided by the pubo analis fibers of the pubo coccygeus. In Hirschsprung's disease the pattern is unmodified. At rest there is continuous rhythmical activity, low amplitude rectal waves being accompanied by an increase in amplitude of these waves. The resting pressures, though raised, are not markedly so. With rectal distention no fall in pressure occurs below the resting level as occurs in the normal. Rhythmical activity persists and, providing the stimulus is sufficient, a rise in base line pressure and amplitude of rhythmical wave occurs. This forms the basis for a physiological test for Hirschsprung's disease. Es presentate un methodo permittente le obtention simultanee de un registration del profilo del pression anorectal e de un electromyographia e un pneumographia del sphinctere anal. Es describite le transductores e le registrator usate, insimul con le methodos e le conditiones del application practic. Esseva studiate 24 juveniles normal e 47 con morbo de Hirschsprung. Es comparate e contrastate registrationes in stato de reposo e in statos de responsa a distension e deflation rectal. Es formulate un theoria in re le activitate del sphinctere interne e le possibilitate de reguardar alterationes in illo como base de un diagnose de morbo de Hirschsprung. Es presentate un methodo permittente le obtention simultanee de un registration del profilo del pression anorectal e de un electromyographia e un pneumographia del sphinctere anal. Es describite le transductores e le registrator usate, insimul con le methodos e le conditiones del application practic. Esseva studiate 24 juveniles normal e 47 con morbo de Hirschsprung. Es comparate e contrastate registrationes in stato de reposo e in statos de responsa a distension e deflation rectal. Es formulate un theoria in re le activitate del sphinctere interne e le possibilitate de reguardar alterationes in illo como base de un diagnose de morbo de Hirschsprung.