What Happens When You Don't Get Enough Fiber?
Low fiber has been linked to a variety of conditions and diseases, primarily of gastrointestinal origin, such as constipation, diverticulosis, colon cancer, irritable bowel syndrome, ulcerative colitis, hernias from chronic straining, gastric ulcers, and appendicitis.
Heart disease can be reduced with increasing fiber intake because fiber lowers triglycerides and increase HDL cholesterol (the good cholesterol). Type 2 Diabetes can be improved with dietary fiber. Obesity can be prevented with dietary fiber because it increases the time needed to chew, increases caloric loss through the stool, lowers or normalizes blood sugar with fewer spikes, and makes the person feel full sooner so the person eats less.
Below, I’ve explained the undesirable side effects of not consuming enough fiber.
Side effects of not consuming enough fiber
Constipation
A constipated patient may be asymptomatic or may have:
· Abdominal bloating
· Pain on defecation
· Rectal bleeding
· Unexpected diarrhea
· Low back pain
Other symptoms may be due to a have difficult rectal evacuation:
· A feeling of incomplete evacuation
· Digital manual extraction
· Tenesmus-feeling of having to go
· Enema retention
These signs and symptoms are grounds for particular concern:
· Rectal bleeding
· Abdominal pain
· Inability to pass flatus (gas)
· Vomiting
· Unexplained weight loss
Questions regarding the onset of constipation may help define the cause, whether in terms of changes in diet, new medications, travel, or associated psychosocial difficulties (stress) at that time. Airplane travel is a common cause of constipation due to dehydration in the plane’s cabin. Exercise stimulates bowel motility while inactive lifestyles do the opposite
Chronic constipation can lead to hemorrhoids. Hemorrhoids can flare up and cause pain at rest, pain with defecation, and rectal bleeding. Once hemorrhoids develop, they rarely go away on their own. However, the symptoms can wax and wane depending on the level of fiber intake. Radiofrequency ablation and surgery are two treatment options for symptomatic hemorrhoids.
Diverticulosis
Diverticulosis is a condition in the large colon where little pouches form internally that become inflamed. These outpouchings happen when the inner layers of the large bowel (colon) push through defects in the outer muscular layers. It is most common in the left colon known as the rectosigmoid colon. This can lead to abdominal pain and pain with bowel movements. Untreated, it can lead to diverticulitis which is an infection in the colon that is more serious. Mild cases can be managed with liquids only for a few days, while more severe cases may require antibiotics and hospitalization.
Irritable Bowel Syndrome
Irritable Bowel Syndrome may be caused by low fiber and other conditions such as:
Diet: Diets low in fiber content or containing extremely sweet or spicy foods.
Intolerance to food items: Poor digestion of the sugars lactose (in most dairy and processed items), fructose (found in syrups), and sorbitol (found in fruits and dried fruits).
Infections: Bacterial infections in the digestive tract such as gastroenteritis (even after the microorganism has been cleared).
Excessive bacteria: Increased number of bacteria in the small intestine or a change in their type usually due to previous infections or antibiotics.
Emotional stress: emotions such as anger, anxiety, nervousness, and stress
Irritable Bowel Syndrome is categorized based on symptoms.
IBS-C (constipation-predominant): The person alternates between constipation and normal stools. Eating may cause abdominal spasms or severe pain.
IBS-D (diarrhea predominant): The patient suffers from diarrhea soon after getting up or after he/she eats something. Sometimes, the bowel movement may be involuntary, and the person may need to make frequent urgent visits to the toilet.
IBS-M (alternating constipation and diarrhea)
IBS-U for unclassified or those that are not in the above categories
Diabetes and Low Fiber
Low fiber has been linked to the development of diabetes (Type 2) and to poor glucose control, both of which can lead to obesity. Likewise, obesity can lead to Type 2 diabetes, increased cholesterol, and increases the risk of many types of cancer. Diabetes is linked to cardiovascular disease, heart attacks, peripheral artery disease, and stroke.
Cardiovascular Disease and Low Fiber
Fiber lowers triglycerides, raises good cholesterol, and lowers blood pressure, all of which reduce cardiovascular diseases such as heart attacks and strokes.
As you can see, low fiber diets can lead to a variety of other problems such as constipation, hemorrhoids, diverticulosis/diverticulitis. All of these conditions can cause pain, bloat, and bleeding. The more serious diseases that take years to develop, such as heart disease and cancer, mean that dietary fiber needs to be introduced at an early age and continued into adulthood.
References
US National Library of Medicine. Constipation. MedlinePlus. Available at https://medlineplus.gov/constipation.html. Updated: May 7, 2019; Accessed: July 5, 2019.
Lu PL, Mousa HM. Constipation: beyond the old paradigms. Gastroenterol Clin North Am. 2018 Dec. 47 (4):845-62. [Medline].
Wald A. Constipation: pathophysiology and management. Curr Opin Gastroenterol. 2015 Jan. 31(1):45-9. [Medline].
National Institutes of Health. Diverticular disease. September 2013; Accessed April 14, 2017. Available at: http://www.niddk.nih.gov/health-information/health-topics/digestive-diseases/diverticular-disease/Pages/facts.aspx.
Jacobs DO. Clinical practice. Diverticulitis. N Engl J Med. 2007 Nov 15;357(20):2057-66.
Yamada T, Alpers DH, Kaplowitz N, et al (eds). Textbook of Gastroenterology. Philadelphia: Lippincott Williams & Wilkins; 2003.
Dr. Kimberly Langdon
Dr. Kimberly Langdon is a retired University-trained obstetrician/gynecologist with 19-years of clinical experience. She delivered over 2000 babies to mothers in a suburban Midwestern community.
