Causes of constipation in the elderly

Constipation in elderly patients, in most cases, is due to multifactorial causes, among which immobility stands out in a very important way. It has been described in constipated and sedentary adults that physical exercise, regardless of fiber in the diet and water intake, improves defecation pattern and colonic transit time.

Other possible causes of constipation can be local factors at the anal or intestinal level, alterations in some eating habits, the taking of drugs for the treatment of the different comorbidities present in the elderly, and metabolic, endocrine and neurological alterations. For all this, a correct methodology in the collection of the clinical history and an adequate comprehensive geriatric assessment is essential.

Among the most frequent causes of constipation, it is worth highlighting a diet low in fiber, which is associated with a decrease in the volume of stool, as well as a slower intestinal transit. The ingestion of low amounts of liquids is also associated with the same effects, also producing dry and hard stools, which are more difficult to expel.

Anorectal diseases, especially hemorrhoids and anal fissures, which cause local pain, are also a common cause of constipation, as the individual inhibits the defecation reflex to avoid pain. Intestinal strictures secondary to surgery, ischemia, or radiotherapy, as well as the presence of megacolon (extraordinarily long colon), can also be a cause of constipation.

Obviously, when faced with new-onset constipation, the possibility of a colon or rectal neoplasm that causes narrowing of the intestinal lumen or decreased mobility must always be ruled out.

Among the metabolic diseases frequently associated with constipation, hypothyroidism is noteworthy, which is relatively common in the elderly and is often not very symptomatic. In addition, there are frequent alterations such as hypokalemia, frequently caused by diuretics (which are commonly used in the elderly) or hypercalcemia, both of which slow down intestinal transit. Paradoxically, there are some cases of stopping the bowel movement due to hypermagnesemia, although it is well known that magnesium has good laxative properties.

Many neurological diseases can cause constipation. It is worth highlighting Parkinson's disease, which causes immobility and slowing down of the smooth muscles, diseases of the spinal cord (in any location, but preferably cervical) and dementias of any type, due to immobility and other associated complications. Other neurological diseases that can cause constipation are cerebrovascular diseases or autonomic neuropathies, such as diabetic polyneuropathy.

Likewise, acute confusional syndrome, anxiety and depression, both by themselves and by the drugs used for their treatment, can also promote constipation.

Certain systemic diseases can cause constipation on their own, such as amyloidosis or scleroderma.

Drugs are a major cause of constipation that can be reversible. In particular, opiates are worth noting, but also all those drugs with some anticholinergic activity, especially tricyclic antidepressants and some antiparkinsons, non-steroidal anti-inflammatory drugs, antacids such as aluminum and calcium carbonate, metals such as iron and antihypertensive drugs such as verapamil. It is well known that the abuse of laxatives, especially those that stimulate mobility, causes constipation.

A very frequent functional cause is the repeated cancellation of the defecation desire, because it occurs at times and locations that are considered inappropriate; in the case of hospitalized or institutionalized elderly, the lack of privacy at that time can make defecation difficult.