Comparison of small-bowel motility of the human jejunum and ileum.

Background: Knowledge about human cyclic fasting motility (MMC) and the postprandial response is mostly based on manometric findings in the upper small intestine. Hardly any data exist on human ileal motility, as the acquisition of data has been limited by methodological concerns. The aim was to study human jejunal and ileal motility in an optimized manometric setting.

Methods: Solid-state 24-h-manometry was performed in the jejunum and ileum of healthy individuals, applying a strict protocol for fasting, resting, and the consumption of a standardized meal. Both visual qualitative and validated computerized quantitative contraction and propagation analysis were performed.

Key Results: MMC occurs in similar frequency in the jejunum and ileum, but it was significantly shorter in the jejunum at night. By many characteristics, ileal motility was less intense and propagative than jejunal: less migrating clustered contractions, and slower propagation velocity and shorter distance in phases II and III, and postprandially - possibly slowing and enhancing nutrient absorption. Prolonged propagated contractions in some individuals were identified as a unique ileal propulsive pattern. Postprandially, an abrupt conversion to a digestive motility pattern occurs simultaneously independent of the region.

Conclusions & Inferences:   We found similar basic phenomena of fasting and postprandial motility in the jejunum and ileum of healthy humans. However, different calibration of propagative and contractile activity and special motor events in the ileum may account for a different physiological role in digestion. Future studies of small-bowel motility in healthy and diseased subjects focusing on segmental differences of proximal and distal intestine may be rewarded.