Figure 5. Haustral Activities.

(A) Isolated pressure transients that are confined to regularly spaced sensors. Here 8 sensors are showing isolated pressure transients, the sensors are 4 cm apart, likely reflecting narrowing of the lumen created by haustral boundary contractions. Of note is that this pattern does not appear to propagate to other sensors. Control subject, baseline. Sensor P36 is 45 cm from anal verge. (B) Rhythmic 3 cycles/min pressure transients dominate the activity. The activity centers on sensor 31, 27 and 22, which is in the order of the spacing of haustral boundaries. From a patient with constipation; sensor P36 is 75 cm from anal verge. (C) Isolated pressure transients occurring at a sustained 3 cycles/min rhythm, no activity is seen in adjacent sensors. Duration of recording is 3.5 min. This represents 4 cm of colon covering 5 sensors. (D) Activity in 5 consecutive sensors occurring in an apparent erratic manner, and with marked differences in pressure amplitude. This activity is very similar to that occurring within haustra of the rabbit colon²⁵ and similar to segmentation activity in the small intestine¹⁷ hence identified here as segmentation. The duration of the recording is 17 min. The figure covers 5 cm of the colon. From a patient with constipation. (E) From the same patient as (D). The erratic activity changed into synchronized activity; at the half point of the recording, the synchronization decreases. The duration of the recording is 17 min. The figure covers 5 cm of the colon. This figure is a small part of Fig. 6A.