The proximal colonic motor response to rectal mechanical and chemical stimulation

Am J Physiol Gastrointest Liver Physiol. 2002 Mar;282(3):G443-9. doi: 10.1152/ajpgi.00194.2001.


We aimed to determine whether rectal distension and/or infusion of bile acids stimulates propagating or nonpropagating activity in the unprepared proximal colon in 10 healthy volunteers using a nasocolonic manometric catheter (16 recording sites at 7.5-cm spacing). Sensory thresholds and proximal colonic motor responses were assessed following rectal distension by balloon inflation and rectal instillation of chenodeoxycholic acid. Maximum tolerated balloon volume and the volume that stimulated a desire to defecate were both significantly (P < 0.01) reduced after rectal chenodeoxycholic acid. The frequency of colonic propagating pressure wave sequences decreased significantly in response to initial balloon inflations (P < 0.05), but the frequency doubled after subsequent chenodeoxycholic acid infusion (P < 0.002). Nonpropagating activity decreased after balloon inflation, was not influenced by acid infusion, and demonstrated a further decrease in response to repeat balloon inflation. We concluded that rectal chenodeoxycholic acid in physiological concentrations is a potent stimulus for propagating pressure waves arising in the proximal colon and reduces rectal sensory thresholds. Rectal distension inhibits all colonic motor activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Biomechanical Phenomena
  • Catheterization
  • Chenodeoxycholic Acid / pharmacology*
  • Colon / physiology*
  • Female
  • Gastrointestinal Agents / pharmacology*
  • Gastrointestinal Motility / drug effects
  • Gastrointestinal Motility / physiology*
  • Humans
  • Male
  • Middle Aged
  • Physical Stimulation*
  • Pressure
  • Rectum / physiology*
  • Sensory Thresholds


  • Gastrointestinal Agents
  • Chenodeoxycholic Acid