There is a high prevalence and wide spectrum of gastrointestinal symptoms in spinal cord injury. Abdominal bloating and constipation are primarily related to specific spinal cord levels of injury, whereas abdominal pain and fecal incontinence are primarily associated with higher levels of anxiety. Based on our findings, further physiologic and psychologic research studies in spinal cord injury patients should lead to more rational management strategies for the common gastrointestinal symptoms in spinal cord injury.

IBS patients demonstrated altered autonomic responses to feeding and colonic distension. Further studies should determine whether these alterations could explain the postprandial exacerbation of symptoms in IBS.

influences on antegrade and retrograde tonic reflexes in the colon and rectum. Am J Physiol Gastrointest Liver Physiol 287: G962-G966, 2004. First published July 1, 2004; doi:10.1152/ajpgi.00460.2003.-Tonic reflexes in the colon and rectum are likely to be important in health and in disorders of gastrointestinal function. The aim of this study was to evaluate the fasting and postprandial "colorectal" and "rectocolic" reflexes in response to 2-min isobaric distensions of the colon and rectum, accounting for enteric sensation, compliance, and distending balloon volume. In 14 healthy fasting subjects, a dual barostat assembly was positioned (descending colon and rectum). A 2-min phasic distension was performed in the colon and rectum in random order while the opposing balloon volume was recorded. Sensation (phasic distension) and compliance (ramp distension) were also determined. The experiment was repeated postprandially. Colonic distension resulted in significant rectal tonic contraction in the fasting (rectal volume change: Ϫ35.4 Ϯ 8.4 ml, P Ͻ 0.01) and postprandial (Ϫ22.2 Ϯ 8.4 ml, P Ͻ 0.01) states. After adjustment for colonic sensitivity, for compliance, and for distending balloon volume, the rectal volume change remained significant; the extent of the tonic response, however, correlated significantly with increasing pain score (P Ͻ 0.01). In contrast, rectal distension did not produce a significant tonic response in the colon (fasting: Ϫ6.5 Ϯ 7.3 ml; postprandial: 2.7 Ϯ 7.3 ml), either unadjusted or adjusted for rectal sensitivity, compliance, and distending balloon volume. In conclusion, the colorectal reflex, but not the rectocolic reflex, can be readily demonstrated both before and after a meal in response to a 2-min isobaric distension in the colon and rectum, respectively. Although the presence of the colorectal reflex does not depend on colonic sensitivity or the volume of the distending colonic balloon, these factors modulate the reflex, especially in the fasting state.