With age, the muscular contractions that initiate swallowing slow down, increasing pharyngeal transit time Nikhil et al, This may lead to swallowing difficulties dysphagia , which can increase the risk of choking and the feeling that food is stuck in the throat.
Up to In general, the motor function of the GI tract is relatively well preserved in healthy older people, but there are significant changes in oropharyngeal and oesophageal motility. In the very old, impaired oesophageal motility is common; oesophageal peristalsis weakens with age Gutschow et al, and peristalsis may no longer be triggered by each swallow.
Both upper and lower oesophageal sphincters lose tension; the lower one in particular undergoes a reduction in pressure, resulting in problems such as dysphagia, reflux and heartburn Grassi et al, The stomach acts as a reservoir for food, allowing us to eat at regular intervals.
With age, it cannot accommodate as much food, primarily because its wall loses elasticity. As a normal part of digestion, the stomach secretes gastric juice containing hydrochloric acid and pepsin. This can compromise the bioavailability of certain drugs, including vitamin B12, and lead to disorders such as chronic atrophic gastritis.
There is also an age-related reduction in mucus-producing goblet cells, which results in reduced secretion of protective mucus and therefore a weakened mucosal barrier. Gastric bicarbonate HCO 3- and mucus normally provide an alkaline layer to defend the stomach lining against gastric juices; however, research suggests that advancing age is associated with a decline in HCO 3- secretion Saber and Bayumi, The protective prostaglandin content of mucus also decreases with age, making older people more prone to gastromucosal injury such as lesions and ulcers, especially after ingesting non-steroidal anti-inflammatory drugs, which are commonly taken by older people.
Finally, gastric emptying slows down with age; this means food remains in the stomach for longer, prolonging satiation and reducing appetite Nieuwenhuizen et al, The main function of the small intestine is to digest and absorb food.
It produces a range of digestive enzymes, supported by the pancreas and liver. Absorption of nutrients occurs in the jejunum and ileum, the second and third regions of the small intestine. The lining of the small intestine is shaped into microscopic folds villi , which increase the surface area available for absorption.
Although an age-related reduction in villus height has been shown, the impact on nutrient uptake does not seem to be clinically significant Drozdowski and Thomson, There is evidence that the production of the enzyme lactase decreases with age, making older people more prone to lactose intolerance Di Stefano et al, ; lactase is created following instruction from the LCT gene, which becomes less active over time.
Populations of certain bacteria that reside in the small intestine have been shown to increase as we age, leading to bloating, pain and decreased absorption of nutrients such as calcium, folic acid and iron. This can have a negative effect on health. In addition, PPIs have been shown to provoke bacterial overgrowth in the small intestine, which may exacerbate NSAID-induced small intestinal injury and foster the development of systemic conditions, including inflammatory bowel disease, diabetes and autoimmune diseases Fujimori, As already mentioned, oesophageal peristalsis slows with age, but research has recently shown that small intestinal transit time does not seem to be affected Fischer and Fadda, In contrast, there is an age-related slowing down of colonic transit caused by a decline in propulsive activity of the colon, which is associated with a reduction in neurotransmitters and neuroreceptors Britton and McLaughlin, This causes a delay in colonic transit of waste, leading to constipation Wiskur and Greenwood-Van Meerveld, Peristalsis is also affected by the age-related atrophy of the mucosa and muscle layers of the colon.
The walls of the colon sag, prompting the formation of pouches diverticuli. Straining to eliminate faeces may put additional pressure on weakened blood vessel walls, giving rise to haemorrhoids. The rate of cell division declines in the digestive epithelium, which cannot repair and replace itself as well as it needs to.
There is also a drastic age-associated rise in the incidence of several gut pathologies including cancer of the colon — in fact, age is the key risk factor for colorectal cancer. Recent studies indicate that ageing induces changes in the DNA of epithelial intestinal cells, particularly in the colon; this process — known as DNA methylation — is believed to play a significant part in the development of colorectal cancers Masoro and Austad, The ageing process mimics the intestinal microbe profile that accompanies inflammatory bowel diseases and obesity Neish, The commensal microorganisms inhabiting the lumen of the colon are prevented from entering surrounding tissues by a single layer of epithelial cells that form an impermeable mucosal barrier.
As the barrier function of the mucosal immune system is impaired, the incidence of GI pathogen infections is higher — and is a major cause of morbidity and mortality in older people Mabbott et al, With age, the pancreas, which generates four major digestive enzymes, decreases in weight and some of its tissue undergoes fibrosis. Its exocrine function is impaired and the secretion of chymotrypsin and pancreatic lipase reduced Laugier et al, , adversely affecting the ability of the small intestine to digest food.
The liver undertakes more than functions for the body; as it shrinks with age and blood flow to it decreases, its functional capacity also decreases Drozdowski and Thomson, In addition, bile becomes thicker and its salt content diminishes, resulting in higher plasma concentrations of cholesterol, particularly in women Frommherz et al, Drugs are no longer inactivated quickly by the liver and are therefore more likely to cause dose-related side-effects: dosages therefore need to be carefully checked when prescribing for older people.
Journal of Clinical Interventions in Ageing; The Proceedings of the Nutrition Society; 1, Davies AE et al Pharyngeal sensation and gag reflex in healthy subjects.
Lancet; , Ageing Research Reviews; 1, Di Francesco V et al Effect of age on the dynamics of acylated ghrelin in fasting conditions and in response to a meal. Journal of the American Geriatrics Society; 7, Di Stefano M et al Lactose malabsorption and intolerance in the elderly.
Scandinavian Journal of Gastroenterology; 12, Medications taken for high blood pressure or muscle and joint pain can lead to constipation,— so remember your water and activity levels. It is recommended that most people have their first colonoscopy at age This is because the risk of developing polyps in your colon increases at that age. Diverticulosis is quite common in those over age It occurs when the small pouches that line the colon bulge out in weak spots along the intestinal wall.
Some people may have no symptoms when this happens, while others can experience gas, bloating, cramps or constipation. Diverticulosis typically does not require treatment, but when the pocket becomes inflamed, you can develop stomach pain, cramping, fever, chills and vomiting. This can be treated with pain relievers, antibiotics and diet changes. Although a person of any age can develop gastrointestinal reflux disease GERD , it is quite common among older adults. Someone with GERD has stomach acid that backs up into their esophagus, causing heartburn and other symptoms.
Older adults who are obese or who have high triglycerides or diabetes are at a higher risk for non-alcoholic fatty liver disease , a condition where fat accumulates in the liver. Bacterial overgrowth may also lead to decreased absorption of certain nutrients, such as vitamin B12, iron, and calcium. With age, the pancreas Pancreas The pancreas is an organ that contains two types of glandular tissue: Pancreatic acini Islets of Langerhans See also Overview of the Digestive System.
The acini produce digestive enzymes However, these changes do not decrease the ability of the pancreas to produce digestive enzymes and sodium bicarbonate. As the liver Liver The wedge-shaped liver is the largest—and, in some ways, the most complex—organ in the body. It serves as the body's chemical factory, performing many vital functions, from regulating the levels See also Overview of the Liver and Gallbladder See also Overview of the Liver and Gallbladder for a discussion of normal function of the liver and gallbladder.
The large intestine Large Intestine The large intestine consists of the Cecum and ascending right colon Transverse colon Descending left colon Sigmoid colon which is connected to the rectum read more does not undergo much change with age. The rectum Rectum and Anus The rectum is a chamber that begins at the end of the large intestine, immediately following the sigmoid colon, and ends at the anus see also Overview of the Anus and Rectum.
Ordinarily, the Constipation becomes more common see Essentials for Older People Essentials for Older People Constipation is difficult or infrequent bowel movements, hard stool, or a feeling that the rectum is not totally empty after a bowel movement incomplete evacuation.
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