Dietary fiber includes both insoluble and soluble fiber.
Insoluble fiber passes through the intestinal tract largely intact, adding bulk and weight to the stool. It is nonfermentable and helps food to pass more quickly through the stomach and intestines. Insoluble fiber is found in wheat bran, fruit and root vegetable skins, whole wheat, and whole-grain products, as well as seeds and nuts. Other sources include pumpernickel breads; all-bran cereal; butter, lima, pinto, and white beans; split and black-eyed peas; blackberries; boysenberries; raspberries; dried figs and prunes; artichokes; asparagus; Brussels sprouts; corn; parsnips; spinach; winter squash; and turnip greens.
Soluble fiber absorbs liquid to form a gel that eases stool movement. Sources of soluble fiber include fruits, vegetables, beans, barley, and oat bran. Soluble fibers include pectins, gums, starches, some hemicelluloses, and other polysaccharides.
Dietary fiber has been evaluated for effectiveness in constipation.
Griffenberg, L., Morris, M., Atkinson, N., & Levenback, C. (1997). The effect of dietary fiber on bowel function following radical hysterectomy: A randomized trial. Gynecologic Oncology, 66, 417–424.
To evaluate the effect of fiber on bowel function by comparing increased fiber intake with instructions versus regular diet.
Women were randomized into two groups: high fiber (treatment) or regular diet (control). Both groups were evaluated at one, four, and seven months after surgery.
The treatment group received dietary counseling with instructions to increase their dietary intake to 30 to 40 g per day. Patients received all-bran cereal (unmarked) containing 15 g of fiber per bowl. Patients also were encouraged to increase their intake of insoluble fibers (eg, whole-grain, whole-wheat, and pumpernickel breads; all-bran cereal; butter; lima, pinto, and white beans; split and black-eyed peas; blackberries; boysenberries; raspberries; dried figs and prunes; artichokes; asparagus; Brussels sprouts; corn; parsnips; spinach; winter squash; turnip greens).
The study reported on a sample of 35 women with cervical cancer who had a type II or III radical hysterectomy.
University of Texas MD Anderson Cencer Center
This was a randomized controlled trial (RCT).
Patients with higher fiber intake had significantly less cramping abdominal pain and reports of straining, bowel-movement retention, more bowel movements with gas, and made in less than three minutes.
Holma, R., Hongisto, S.M., Saxelin, M., & Korpela, R. (2010). Constipation is relieved more by rye bread than wheat bread or laxatives without increased adverse gastrointestinal effects. Journal of Nutrition, 140, 534–541.
To investigate the effects of rye bread and cultured buttermilk on bowel function, colon metabolism, and gastrointestinal symptoms in adults with constipation.
For three weeks before the beginning of the study, participants were instructed not to use products containing Lactobacillus rhamnosus GG (LGG). At the end of the baseline period, participants were randomized into one of five groups.
Foods considered to have laxative effects (e.g., prunes, flax, fiber products) were only allowed for the laxative group. All participants were permitted laxative use as necessary after first contacting the principal investigator. Participants were to exclude products containing other lactic acid bacteria.
Participants collected all feces for five days during the baseline week, one day during week 1, and five days during week 3. The samples were kept frozen until taken to the study center. Sitzmarks® Radiopaque capsules were used to determine total intestinal transit time (TITT) measurements.
A metropolitan area in Helsinki, Finland
This study had a randomized, unblended, 2 x 2 factorial design (LGG given, LGG not given, rye bread given, rye bread not given).
Patients self-reported the following.
In adults with constipation, bowel function and colonic metabolism may improve more with rye bread consumption than with wheat bread consumption or common laxative use without causing adverse abdominal symptoms. Cultured buttermilk with LGG did not significantly improve bowel function or affect colonic metabolism in this population.
Rye bread consumption may be more effective in relieving constipation than wheat bread or commonly used laxatives in adults. However, the convenience sample of volunteers was small, comprised predominately men, and did not include patients with cancer. Additional study is warranted in a larger population that includes patients with cancer, as well as a balanced number of women and men.
Sturtzel, B., & Elmadfa, I. (2008). Intervention with dietary fiber to treat constipation and reduce laxative use in residents of nursing homes. Annals of Nutrition and Metabolism, 52(Suppl. 1), 54–56.
To determine whether the addition of oat bran to the diets of older adult residents of a long-term care facility would lead to a reduction in laxative use.
The control group (15 patients assigned) received usual diet.
The intervention group had oat fiber containing 8.3 g of nondigestible fermentable fiber and 9.7 g of nondigestible nonfermentable fiber per 100 g incorporated into their diet for 12 weeks.
Single ward of a long-term care facility in Vienna, Austria
The study has clinical applicability to older adult care.
This was a controlled, parallel, blind intervention trial.
Fiber supplementation with oat bran may be an alternative to laxatives for treating constipation in an older adult population.
Increasing fiber supplementation with oat bran may be an alternative to laxative use for treating constipation in older adults. Additional study is warranted in a larger population that includes patients with cancer.
Sutton, D., Dumbleton, S., & Allaway, C. (2007). Can increased dietary fiber reduce laxative requirement in peritoneal dialysis patients? Journal of Renal Care, 33, 177–178.
To explore the extent to which peritoneal dialysis (PD) patients are affected by constipation, how many laxatives they use on a regular basis, and barriers to managing constipation when their dietary fiber is increased.
In stage 1, the investigators established current bowel habits and laxative use. In stage 2 (N = 23), fiber intake was increased by 6 to 12 g per day using a dietary fiber supplement, partially hydrolyzed guar gum (PHGG). Finally, in stage 3 (N = 17), patients' daily diet was modified to include foods naturally high in fiber, aiming for 6 to 12 g per day more than their current intake, and bowel habits and laxative use were monitored.
A stool-and-laxative recording diary was sent to 126 PD patients. Forty-six reported using laxatives. All respondents using laxatives were invited to use a soluble dietary fiber supplement for four weeks, followed by dietary advice to see whether they could achieve the same effect using high-fiber foods.
This was a descriptive study with a three-stage audit and intervention project.
A stool-and-laxative diary was used to measure number of bowel movements per day.
Fiber supplementation may be as effective as laxative treatment in preventing constipation. In addition, fiber supplementation was preferred by patients in this study, as many felt it improved bowel habits without the side effects of stimulant laxatives.
Fiber supplements cost much more than standard laxatives.
Bharucha, A.E., Pemberton, J.H., & Locke, G.R., 3rd. (2013). American Gastroenterological Association technical review on constipation. Gastroenterology, 144, 218–238.
To identify rational, effective, and cost-effective treatment approaches for patients with constipation.
In this evidence-based guideline, material was selected from reviews and focused literature searches of peer-reviewed published studies.
Databases searched, search keywords, and inclusion criteria were not stated.
Studies were excluded if they reported on children or patients with constipation as a secondary symptom caused by problems such as spinal cord injury.
The study has clinical applicability to older adult and palliative care.
Evidence was categorized according to the U.S. Preventive Services Task Force grading system. Rome II criteria were used to define constipation. The resource identified causes of constipation, approaches for assessment, and recommendations for management based on evidence review. In addition to opiates, other causative agents associated with constipation in patients with cancer were antidepressants, anticholinergic agents, vinca alkaloids, vincristine, and cyclophosphamide.
Limited high-quality evidence exists for effective interventions in managing constipation.
National Comprehensive Cancer Network. (2012). NCCN Clinical Practice Guidelines in Oncology: Palliative Care [v.2.2012]. Retrieved from http://www.nccn.org/professionals/physician_gls/pdf/palliative.pdf
The objective of the guidelines is to provide palliative care practice guidelines for patients with cancer, facilitating the appropriate integration of palliative care into oncology practice.
These are consensus-based guidelines.
Included in the guidelines are multiple phases of care with palliative care applications.
The NCCN made recommendations on the following symptoms.
Nutritional support, including enteral and parenteral feeding, should be considered. Appetite stimulants such as megestrol acetate and corticosteroids can be used when appetite is an important aspect of quality of life.
Chemotherapy-Induced Nausea and Vomiting (CINV)
Recommendations include prochlorperazine, haloperidol, metoclopramide, or benzodiazepines. Adding 5-HT3 receptor agonists, anticholinergics, antihistamines, corticosteroids, antipsychotics, and cannabinoids also can be considered. Palliative sedation can be considered as a last resort.
Increase fluid intake, dietary fiber, and physical activity. Opioid-induced constipation should be anticipated and treated prophylactically with laxatives.
Pharmacologic interventions include opioids or benzodiazapines. Scopolamine, atropine hyoscyamine, and glycopyrrolate are options to reduce excessive secretions.
Do not reduce opioid dose for symptoms such as decreased blood pressure or respiratory rate. Palliative sedation can be considered for refractory pain.
For refractory insomnia with no underlying physiologic cause, pharmacologic management includes diazepam, zolpidem, and sedating antidepressants. Cognitive behavioral therapy may be effective. If present, restless leg syndrome can be treated with ropinirole.
Recommendations provide expert opinion/consensus-level suggestions for management of various symptoms. Many recommendations, such as those for CINV, do not agree with current evidence in these areas.