Doris is a healthy 69-year-old woman who has recently had problems with “irregularity”, her polite word for constipation. She thought it was just a symptom of aging, but the problem was really starting to bother her. Despite her embarrassment, she summoned up her courage and talked with her primary care provider (PCP) who ruled out any serious concerns. After asking a few questions, the PCP decided to refer her to a registered dietitian nutritionist (RDN) to evaluate her eating habits. Doris has lots of questions, many of which we will explore here.
What is Considered Normal Bowel Function?
Normal bowel function varies from person to person. Constipation is generally defined as infrequent bowel movements or difficult passage of stools that persists for several weeks or longer. A more specific definition is outlined by the Rome IV criteria as:1
- Fewer than three spontaneous bowel movements per week
- Straining for more than 25% of defecation attempts
- Lumpy or hard stools for at least 25% of defecation attempts
- Sensation of anorectal obstruction or blockage for at least 25% of defecation attempts
- Manual maneuvering required to defecate for at least 25% of defecation attempts
Is Constipation Related to Aging?
Studies suggest that prevalence increases with age, but that constipation is not an inevitable part of the aging process.2 Aging can cause a slight slowing of the movement of contents through the large intestine and a modest decrease in the contractions of the rectum.3 But constipation could also be attributed to more frequent use of certain medications, a decrease in fluid intake, and a decrease in physical activity that often accompanies aging.2,3
Dietary Fiber: How Much and What Type?
For good health, the daily recommended amount of fiber is at least 25 grams for women and 38 grams for men,4 but there are nuances to fiber intake that can affect bowel function. Fiber can be described as either soluble or insoluble. Soluble fiber dissolves in water to form a gummy gel. Sources include dried beans, oats, barley, bananas, potatoes and soft parts of apples and pears. Soluble fiber can slow intestinal transit time and/or solidify loose stools.4
Insoluble fiber does not dissolve in water and helps produce softer, bulkier stools that increase fecal transit time.4 Sources include whole bran, whole grain products, nuts, corn, carrots, grapes, berries and peels of apples and pears. All fiber is important to overall good health and GI function, but insoluble fiber may be more effective than soluble fiber in treating constipation.5 However, the type of fiber consumed is not the only key to bowel health, because the overall diet as well as other properties of fiber can affect stool viscosity and fermentation in the gut.4
Increasing the amount of fiber in the diet gradually will help limit possible side effects such as bloating and gas. When increasing fiber, fluid intake should also increase to as much as 2 liters per day.6 Consuming more than 50-60 grams of fiber daily may lower the body’s ability to absorb some vitamins and minerals.4
A Happy Outcome for Doris
Doris’s constipation doesn’t meet the Rome criteria, but it might be treatable with dietary changes. Doris and her RDN work together to determine dietary changes to increase all types of high-fiber foods and add more fluids. Doris is learning to enjoy whole grain breads and cereals, legumes, and more fruits and vegetables. Thanks to her RDN, Doris is armed with ideas on how to work more of these foods into her daily meals and snacks. Most of all she is relieved that her irregularity is not due to any serious health issue, and it is not just a symptom of aging. Doris is much happier and feeling much better now that she has a more “regular” life.
©2019 Becky Dorner & Associates, Inc.
Becky Dorner & Associates, Inc. (BDA) is a trusted source of valuable continuing education, nutrition resources and creative solutions. Visit our website to sign up for free news and information.
©2020 Becky Dorner & Associates, Inc. Becky Dorner & Associates, Inc. (BDA) is a trusted source of valuable continuing education, nutrition resources and creative solutions. Visit www.beckydorner.com to sign up for free news and information.
- Brasson MD. Rome Criteria for defining constipation. Medscape web site. https://www.medscape.com/answers/184704-23237/what-are-the-rome-iv-criteria-for-constipation. Updated July 4, 2019. Accessed December 2, 2019.
- Academy Nutrition Care Manual. Constipation in older adults. https://www.nutritioncaremanual.org/topic.cfm?ncm_category_id=31&lv1=255616&lv2=255633&lv3=268680&ncm_toc_id=268680&ncm_heading=Older%20Adult%20Nutrition. Accessed December 11, 2019.
- Ruiz AR. Effects of aging on the digestive system. Merck Manual Consumer Version. https://www.merckmanuals.com/home/digestive-disorders/biology-of-the-digestive-system/effects-of-aging-on-the-digestive-system#. Accessed December 2, 2019.
- Duyff, RL. Academy of Nutrition and Dietetics Complete Food and Nutrition Guide. Chicago, IL: Academy of Nutrition and Dietetics; 2017:350-355.
- Freuman TD, Truong-Leikauf M. Nutritional Implications of gastrointestinal disorders. In: Bernstein M, Munoz N. Nutrition for the Older Adult. 3rd Edition. Burlington MA: Jones and Bartlett Learning; 2020: 217-251.
- Cresci G, Escure A. Medical nutrition therapy for lower gastrointestinal tract disorders. In: Mahan LK, Raymond JL. Krause’s Food and the Nutrition Care Process. 14th ed. St. Louis MO: Elsevier, 2017: 525-559.