Assessment of the effect of increased dietary fibre intake on bowel function in patients with spinal cord injury

Abstract

It is common for constipation to occur following severe spinal cord injury (SCI). Although a bowel management program including a high fibre diet is an integral part of rehabilitation, 1 the effect of a high fibre diet on large bowel function in SCI has not been examined. The aims of this study were to assess the nutrient intake of SCI patients, to determine baseline transit time, stool weight and evacuation time and to assess the effect of addition of bran on large bowel function. Eleven subjects, aged 32 ± lO.5 years participated in the study. The level of injury ranged from C 4 to Tl 2 ; only one patient had an incomplete injury. Baseline mean energy intake was 7823± 1443 kJ/d, protein intake 93±21 g/d, carbohydrate intake 209 ± 39 g/d and mean dietary fibre intake 25 ± 8 g/d. Mean baseline stool weight was 128 ± 55 g/d and bowel evacuation time was 13 ± 7.4 min/d. Three subjects who consumed < 18 g dietary fibre/d had low stool weights of 60-70 g/d and two had very delayed transit times that were too slow to enable quantitation. Mean mouth to anus transit time was 51.3±31.2 h, mean colonic transit time 28.2±3.5 h, right colonic transit time 5.9±4.5 h, left colonic transit time 14.5 ± 5.2 h and rectosigmoid colonic transit time 7.9 ± 5.6 h. Following the addition of bran, dietary fibre intake significantly increased from 25 g/d to 31 g/d (P<O.OOl). However, the mean colonic transit time increased from 28.2 h to 42.2 h (P<0.05) and rectosigmoid colon transit time increased from 7.9 to 23.3 h (P < 0.02). Stool weight, mouth to anus, left and right colon transit time and evacuation time did not change significantly. Results of this study suggest that increasing dietary fibre in SCI patients does not have the same effect on bowel function as has been previously demonstrated in individuals with 'normally functioning' bowels. Indeed the effect may be the opposite to that desired. This preliminary study highlights the need for further research to examine the optimal level of dietary fibre intake in SCI patients.

Neurogenic bowel management after spinal cord injury: a systematic review of the evidence

“…[21][22][23] Dietary fiber. There is Level 4 evidence (from one case series; N ¼ 11) 24 that high fiber diets may cause colonic transit time to increase, rather than decrease ( Table 3). The results of the one case series suggest that increasing dietary fiber in SCI patients does not have the same effect on bowel function as has been shown earlier in individuals with normalfunctioning bowels.…”

“…The effect may actually be the opposite of the desired result. 24 Therefore, adding more fiber alone does not improve bowel function. Reflex stimulation of the GI tract.…”

“…Stimulation through abdominal massage seems to have some positive outcomes on colonic function, thus controlled trials are feasible for this intervention and need to be performed. Conservative treatment may also include diet, although the study by Cameron et al 24 sends a cautionary message that dietary fiber may have different effects in people with SCI compared with able-bodied persons. Adding more fiber alone does not improve bowel function; however, more research is needed to assess its effectiveness.…”

Constipation Treatment in Neurological Disorders

“…Increasing dietary fibre may be useful in MS patients to soften faeces, but it is not helpful in patients with severe constipation, as observed in spinal cord injury (Cameron et al, 1996 Abdominal massage decreases severity of constipation and abdominal pain, and increases bowel movements. In health subjects with constipation, the massage has a delayed effect that may occur first after a number of weeks so that it is considered a long-term treatment.…”

Evaluation and Treatment of Neurogenic Bowel Dysfunction – A Review

“…26 Looking specifically at individuals with NBD, a case series of 11 SCI patients reported an increase, rather than decrease in colonic transit time with the use of insoluble fibre. 27 However, the subjects received a very high-fibre diet without proper advice on fluid intake and as such the results are not thought to be relevant to clinical practice. As the insoluble fibre can help bulk and soften the stool, a sensible approach is to adjust its intake according to the stool consistency.…”