Colorectal responses to distension and feeding in patients with spinal cord injury

Abstract

Suttor VP, Ng C, Rutkowski S, Hansen RD, Kellow JE, Malcolm A. Colorectal responses to distension and feeding in patients with spinal cord injury. Am J Physiol Gastrointest Liver Physiol 296: G1344 -G1349, 2009. First published April 9, 2009 doi:10.1152/ajpgi.90408.2008.-The role of the central nervous system in enteroenteric motor reflexes remains controversial. Our aims were as follows: 1) to evaluate colorectal, rectocolic, gastrocolonic, and gastrorectal reflex responses in patients with cervical spinal cord injury (SCI) and 2) to compare these responses with those in healthy subjects. In six patients with SCI (5 male, 42 Ϯ 4 yr) and six healthy control subjects (5 male, 36 Ϯ 5 yr), 2-min phasic distensions were performed randomly via dual-barostat balloons in the colon and rectum. Continuous colonic and rectal balloon volumes were recorded during distensions and after a 1,000-kcal liquid meal. Mean balloon volumes were recorded before, during, and after phasic distensions and over 60 min postprandially. The colorectal response was similar in control subjects and SCI patients (rectal volume reduction ϭ 28 Ϯ 11% and 15 Ϯ 5% in SCI patients and healthy subjects, respectively); the rectocolic response was variable. The gastrocolonic response was present in all subjects (colonic volume reduction ϭ 49 Ϯ 4% and 44 Ϯ 3% in SCI patients and healthy subjects, respectively), with a time effect in the first 30 min (P Ͻ 0.0001) and a group effect in the second 30 min (P Ͻ 0.004). The gastrorectal response was present in four SCI patients and five healthy subjects (rectal volume reduction ϭ 38 Ϯ 4% and 41 Ϯ 3% in SCI patients and healthy subjects, respectively), with a time effect in the first 30 min (P Ͻ 0.0001) but no group effect in the second 30 min. Intact neural transmission between the spinal cord and higher centers is not essential for normal colorectal motor responses to feeding and distension; however, a degree of central nervous system and neurohormonal modulation of these responses is likely. gastrocolonic; gastrorectal; rectocolic; colon; spinal injury THE STUDY OF REFLEX MOTOR activity within the gut has received increasing attention in recent years. In reference to the colorectum, previous studies demonstrated that distension of the descending colon can be associated with an increase in rectal tone, a phenomenon termed the "colorectal" reflex (14,20). In addition, rectal distension provokes an opposite effect, with a reduction in colonic tone and phasic motor activity, a phenomenon termed the "rectocolic" reflex. In healthy subjects, Law et al. (14) found that the rectocolic response was clear and reproducible but the colorectal response was more subtle; conversely, studies from our unit demonstrated a clear and definitive colorectal response and a more variable rectocolic response (20).The neural pathways involved in these reflexes in humans, particularly the roles of intrinsic vs. extrinsic pathways and the role of the spinal cord, remain unclear. Patients with complete spinal cord injury (SCI) provid...

Rectal hyposensitivity for non-noxious stimuli, postprandial hypersensitivity and its correlation with symptoms in complete spinal cord injury with neurogenic bowel dysfunction

“…12 On the other hand, in SCI patients's rectal tone decreased after food compared with their own fasting values. The presence of impaired gastrorectal response in our patients disagrees in part with a recent report 10 in which four out of six cervical SCI patients and five HS showed an increase in rectal tone, however, with no group effect in the second 30 min. As for HS, this data supports previous results showing that rectal tone does not vary after food.…”

“…Only one of the seven cervical SCI patients reported pain sensation, which implies that for noxious stimulus an intact neural transmission between the spinal cord and higher centres is essential. In contrast, Suttor et al 10 claim that an intact neural transmission between the spinal cord and higher centres is not essential for a normal colorectal motor response to feeding. The discrepancy may lie in that they elicit non-noxious stimulus.…”

“…This idea supports in part the impression of other investigators in the sense that chronic constipation may be at least partly attributable to anorectal dysfunction after SCI. 10 If so, the pharmacological approach in SCI patients must be redirected in order to act in a localized manner. Topical rectal therapies as first-line agents are at present recommended in patients with disease limited to the left colon or with active rectal inflammation.…”

“…Suttor et al 10 maintains that the preservation of the colorectal reflex and the colonic tonic response to a meal in cervical SCI indicates that these reflexes do not depend on neural transmission through central spinal pathway, rather they use intrinsic nerves or pre-vertebral pathways for colorectal reflex, and vagal and neurohormonal pathways for gastrocolonic reflex. In a PITH (destruction of the lumbar and sacral cords) guinea pig model it has been demonstrated that the intrinsic rectorectal and rectoanal inhibitory reflexes remain unchanged after removal of the extrinsic sacral excitatory neural pathway (pelvic nerves), 29 suggesting that intrinsic cholinergic excitatory and nitrergic inhibitory pathways mediate the reflexes.…”

“…We evaluated rectal tone after food, which in healthy subjects showed no variation but which in constipated patients increased significantly as measured by the baseline bag volume, indicating that food diminished rectal tone in constipated patients. 9 Suttor et al 10 reported that intact neural transmission between the spinal cord and higher centres are not essential for normal colorectal motor response. On the other hand, visceral sensitivity testing may be a future requirement, in addition to the American Spinal Injury Association (ASIA) criteria, to assess the completeness of cord lesions in patients diagnosed with complete spinal cord transsection, as some subjects report the sensation of distension of the rectum.…”