[Methods for studying the motility in the small intestine, colon and recto-anal area]

Small bowel and colonic motility can be studied either indirectly by the determination of the transit time or directly in recording bowel contractions. Small bowel transit time is usually assessed with the H2-breath test when colonic transit time is mainly determined fluoroscopically in studying the progression of radiopaque markers along the large bowel. Scintigraphic techniques are promising but not routinely used techniques. In the small bowel, gut contractions are recorded with manometric probes. To study colonic movements, electromyography is more usual than manometry. In both cases, whatever the technique employed, the large inter- and intra (topographic and nycthemeral) variability need to be considered for the interpretation of the motor patterns. Rectoanal studies led to consider two aspects: how the rectum acts as a reservoir and anal function. The ability of the rectum to be a reservoir is assessed either by the volume remaining in the rectum during the rectal perfusion with saline or by the determination of the maximal tolerable volume of distension. Manometry and/or electromyography test anal function at rest and during a rectal distension, straining or a voluntary contraction.