Zusammenfassung

BACKGROUND: Continence and defecation require coordination between colonic motor patterns and internal anal sphincter relaxation, yet these relationships are not well understood. AIMS: Our aim was to investigate the coordination between human colonic motor patterns and anal sphincter activity. METHODS: High-Resolution Colonic Manometry (HRCM) was performed using an 84 sensor water-perfused catheter (1 cm spacing) in 14 healthy subjects. Colonic motor patterns and anorectal activity were recorded at baseline and provoking conditions (after a meal, balloon distensions, and luminal bisacodyl administration). RESULTS: A highly rhythmic alternation of contraction and relaxation of the internal AS in resting condition was observed in all subjects: a low-frequency rhythmicity at 1.2 ± 0.3 cpm with slowly developing and declining contraction, and a high-frequency rhythmicity at 15.0 ± 2.7 cpm superimposed on the slow rhythmicity. The High Amplitude Pressure Wave (HAPW) (Chen et al., 2017) was not routinely associated with IAS relaxation. However, 62.5% of HAPWs were associated with a brief transient relaxation at the onset of the HAPW in the proximal colon, which did not last for the duration of the HAPW. Gas expulsion was associated with Simultaneous Pressure Waves (SPWs), pan-colonic pressurizations that penetrated into the anal canal and were most often associated with strong relaxation of the IAS. Many HAPWs terminated in the mid or descending colon but were immediately followed by an SPW and this was accompanied by IAS relaxation. A total of 61 independent SPWs with a mean amplitude of 26.3 ± 7.9 mmHg, were associated with 50.2 ± 12.7% % IAS relaxation from 65.1 ± 15.6 mmHg to 31.5 ± 11.3 mmHg. Bisacodyl induced SPWs of highest amplitude (30.3 ± 4.7 mmHg), that were followed by 63.8 ± 9.0% IAS relaxation, compared to SPWs occurring at baseline of 23.8 ± 5.6 mmHg associated with 44.3 ± 12.4% IAS relaxation. Duration of relaxation was correlated neither with the amplitude of SPW nor the percentage of IAS relaxation. ...