digestive

Digestive system

Introduction

Most problems of the digestive system are not specific to older people. This means that they are not usually caused by ageing itself. But they may occur more frequently and presentation and complications may change as the body ages.

Some age-related changes to the digestive system and their consequences

Pouches (diverticulae) may develop near the upper (throat) end of the esophagus (gullet) or at the bottom end of the gut, at the colon (large bowel). Full pouches may cause obstruction and may leak food into the windpipe. Diverticulitis is more common in men. It is increasingly common in developed countries; one possible cause is a lack of dietary fiber.
Loss of coordination of muscle contractions of the esophagus in some octogenarians.
Herniation (protrusion through a gap in the diaphragm muscle) of the lower esophagus and upper part of the stomach (hiatus hernia) is extremely common. The major cause is thought to be muscle weakening.
Gallbladder bile has an increased phospholipid and cholesterol content. This leads to gallstones, which are common in people aged over 70 years. Around half may be asymptomatic but in others the stones may block the bile duct and affect its functioning, causing pain and jaundice.
Anorectal muscle and anal sphincter changes and reduced elasticity of the rectal wall may sometimes lead to faecal incontinence.
Tastebud sensitivity to "salty" and "sweet" decreases, which may reduce appetite. Those who wear dentures may also lose sensitivity to sour and bitter tastes.

Dysphagia

This can mean problems:

Shifting food from the front of the mouth to the back of the throat (e.g. tumors, strictures, abscesses, stroke).
Swallowing once food reaches the back of the throat (degenerative neuromuscular diseases, upper esophageal sphincter function).

Gastro-esophageal reflux disease (GERD)

The chest pain of GERD may mimic or co-occur with heart disease, making diagnosis more problematic. GERD has a higher prevalence in older than in younger people.

Complications include:

Regurgitation.
Bleeding.
Dysphagia.

Gastroduodenal and peptic ulcers

These have a greater incidence in older people, who have:

Increased Helicobacter pylorii levels.
Chronic use of NSAIDs (e.g. in patients with joint inflammation).
Impaired defense mechanisms.

A lack of obvious symptoms is common, and the main complications (bleeding and perforation) are more likely to be serious or fatal. Hence the mortality rate is higher than in younger people.

Colonic ischemia

This is the most common vascular disorder of the intestines in older people, but is still uncommon. Recurrent attacks occur in fewer than 10% of patients.

In most cases, it is difficult to establish the cause but possible contributory factors include:

Atherosclerosis.
Hypotension.
Dehydration.
Congestive heart failure, use of digitalis, cardiac arrhythmias.

Bowel movements

Diarrhea

Diarrhea in old age has the same causes as in younger people . But in older people it may be:

Especially debilitating.
Recurrent with frequent re-infections in those living in institutions.
(See also Infections).

Constipation

Constipation is an alteration in bowel habits for the individual. It may be:

Decreased frequency of bowel movements.
The difficult passage of hard faeces.

It may be caused by:

Ignoring or over-riding the urge to defaecate due to immobility, poor toilet arrangements, pain or confusion.
Poor diet, dehydration.
Gastrointestinal disease (including cancer).
Drugs.
Hypothyroidism.
Food remaining in the gut for longer (slow transit time). Physical activity may help in this case.
Poor digestive system muscle tone.

Faecal incontinence

Faecal incontinence may be due to:

Leaking with faecal impaction (known as faecal retention with overflow) – due to constipation, poor diet, dehydration or local pathology.
Diarrhea.
Neurological problems
Trauma (e.g. surgery, repeated straining).
Immobility, confusion.
Rectal prolapse (descent of the rectum outside the anus).
Failure to get to or identify a suitable place is considered in rehabilitation.

Teeth

Older people may have yellowing teeth which are vulnerable to caries as dentine is exposed through:

Poor oral hygiene.
Erosion (dietary acids such as fruit juices; medicines).
Abrasion (wear).

The little dental pulp that remains in the older person has a poorer blood and nerve supply.

Tooth changes in older age.

The presence of 20 or 21 teeth in old age has been used by the World Health Organization as an oral health goal. Many old people do not have any natural teeth, usually because of periodontal disease (disease of the gum tissue around the tooth roots).
This is accelerated by:

Poor oral hygiene, sugar- or acid-rich diet, lack of visits to a dentist.
Age-related decrease in saliva production.
Age-related bone changes so that the tooth roots become exposed and the teeth loosened.
Atrophy of the mucous membranes so that oral surfaces are easily traumatized.
Where the root itself is exposed, root caries may occur. This is almost exclusively a disease of the older person.

Diet

Age-related weight loss versus malnutrition

The body loses weight with age due to:

Reduced body water content.
Reduced bone mass (osteoporosis).
Conversion of muscle to fat.
Thinning connective tissue.
Reduced appetite.
Poor diet.
Depression/loneliness.
Illness.

In itself weight loss does not cause health problems. But it makes older people more vulnerable to malnutrition, with deficiencies in:

Vitamin C
Vitamin D (a factor in osteomalacia)
Tissue repair process.
Immune function.

"Food is an important part of a balanced diet."
Fran Lebowitz

Reasons for a poor diet

There are pathological, environmental and age-related reasons for poor nutrition in older people:

Poor appetite may result from disease (e.g. cancer) or social factors such as poverty.
Dental problems will alter the choice of food.
Blunting of taste may affect the type of food eaten.
Older people take longer to eat and so may not be able to finish a meal.
Ignorance about diet or a lack of cooking skills (e.g. in widowers)
Adherence to inappropriate special diets.
Physical disabilities may prevent the buying, preparing or cooking of food.
Living alone is generally associated with a poorer diet.
Apathy (depression) and self-neglect and lack of insight (dementia).
Gastrointestinal problems or disease.
Apraxia.
Other health problems.
Side effect of medications.

Vitamin B12 deficiency

Pernicious anemia is especially common in older people. It is caused by a lack of vitamin B12 and is not a dietary problem. It appears to be an autoimmune disease and is more common in people with other autoimmune diseases.