Anorectal Function

The anus is much cleverer than we like to think. Or maybe we don’t like to think about it at all, unless it fails or is too up tight. It is, in fact, two sphincters in one, the outer one under conscious control, the inner not. It is exquisitely sensitive, distinguishing accurately between gas, fluid and solid.
The control of defaecation, so essential for socialization, requires the coordination of colonic propulsion, anorectal sensation and relaxation of internal and external sphincters and the muscles of the pelvic floor.
Continence is protected by the response of the external sphincter and puborectalis muscles to rectal distension and increases in intra-abdominal pressure.
Over the course of nearly twenty years, we worked with colleagues in surgery to describe the function of the anal sphincter in health and disease and helped devise and perfect new procedures to treat disorders of anal sphincter mechanism.

  1. Read, N.W. and Bannister, J.J. (1985). Anorectal manometry: Techniques, measurements in healthy subjects and patients with anorectal disease. In: Proctology and the Pelvic Floor. (Eds. M. Henry and M. Swash). Butterworths, Sevenoaks, pp.65-87.
  2. Bannister, J.J., Davison, P., Timms, J.M., Gibbons, C.G., Read, N.W. (1987). Effect of the stool size and consistency on defaecation. Gut 28: 1246-1250.
  3. Bannister, J.J., Gibbons, C., Read, N.W. (1987) Preservation of faecal continence during rises in intra-abdominal pressure. Is there a role for a flap valve in maintaining normal continence. Gut 28: 1242-1245.
  4. Rao, S.S.C., Holdsworth, C.D., Read, N.W., Davison P.A., Bannister J.J. (1987) Anorectal sensitivity and reactivity in patients with ulcerative colitis. Gastroenterology 93: 1270-1275.
  5. Read, N.W., Sun, W.M. (1988) Disorders of the anal sphincter. In: Functional Bowel Disease (Ed. W.J. Snape), Plenum Press.
  6. Edwards, C.A., Baxter, J., Brown, S., Bannister, J.J., Read, N.W. (1989) Effect of bile acids on anorectal function in humans. Gut 30: 383-386.
  7. Brown, S., Cann, P.A., Read, N.W. (1990) Effect of coffee on distal colon function. Gut 31: 450-453.
  8. Sun, W.M., Prior, A., Daly, J., Cheam, K., Read, N.W., Grundy, D. (1990) Sensory and motor responses to rectal distension vary according to rate and pattern of balloon inflation. Gastroenterology 99: 1008-1015
  9. Prior, A., Stanley, K., Smith, A.R.B., Read, N.W. (1992) Effect of hysterectomy on anorectal and ureathrovesical physiology. Gut 33: 264-267.
  10. Sun WM. Katsinelos P, Horowitz M, Read NW. (1996) Disturbances in anorectal function in patients with diabetes mellitus and faecal incontinence. Euro. J. Gastro. Hep. 8 (l0): 1007-12.