Constipation in adults

Many people become constipated from time to time. This is known as occasional constipation.

If hard, difficult and unsatisfactory bowel movements become the norm over several months, this may indicate that the person has chronic constipation.

Changes to diet or lifestyle can help to regulate bowel movements.

It is completely normal for stools to differ in appearance from day to day – and this partly depends on what a person has eaten.

However, if the following signs become more frequent and persist for at least 3 months, this is indicative of chronic constipation:

• fewer than 3 bowel movements in a week
• hard, lumpy stool
• difficulty passing stool, often requiring pressing on the abdomen or using a finger to remove some stool from the rectum
• feeling no urge to defecate (pass stool)
• a feeling of incomplete evacuation, i.e., incomplete emptying of the rectum
• a sensation that something is obstructing evacuation
• the sensation of having a bloated stomach

With the exception of bowel movement frequency, none of these symptoms can be measured. It is therefore useful to keep a diary tracking bowel movements over several weeks, in which daily habits can be documented.

The Bristol Stool Scale may be very useful in this regard. This scale describes seven types of stool. Type 6 and 7 stools indicate diarrhea, types 3 to 5 are normal stools, and stools classified as type 1 or 2 indicate constipation.

Constipation occurs when the mechanism for emptying the rectum is not working properly or when the transit of stool through the digestive tract is slower than normal. Intestinal transit time is the term used to describe the time it takes for food to travel from the mouth to the anus, passing through the digestive tract.

If this is slowed down, stools remain in the colon (large intestine) for longer than normal. The colon continuously absorbs water from the stool that builds up there, causing it to become hard and lumpy.

There are many reasons why stool may remain in the colon for longer than normal. These include:

• a low-fiber diet
• dehydration (not drinking enough fluids)
• not moving enough
• deliberately suppressing the urge to defecate (pass stool)
• a sudden change in living conditions – for example, when traveling to a different country

However, these reasons only cause symptoms in certain people who have a natural tendency to become constipated.

The body’s mechanism for emptying the rectum is based on the interaction of relaxing muscle reflexes and intentional control. This process can easily become impaired, for example, due to excessive straining.

Conditions affecting the rectum, such as enlarged hemorrhoids (piles) or a severe prolapse of the pelvic floor can also prevent the normal evacuation of stool.

Other causes of constipation include:

• Intestinal transit problems, up to and including a bowel obstruction caused by structural narrowing of the intestines – this can occur, for example, due to inflammatory conditions such as Crohn’s disease and diverticulitis, due to scarring following abdominal surgery or due to tumor diseases
• Hormonal factors, such as a high progesterone level during pregnancy or, in rare cases, hypothyroidism (underactive thyroid)
• Neurological conditions such as multiple sclerosis or Parkinson’s disease
• Mental health conditions, such as anorexia
• Diabetes mellitus
• Side-effects of certain medication, such as iron supplements, opioid-based painkillers, antidepressants and drugs to treat high blood pressure

It is difficult to accurately determine the prevalence of chronic constipation because different doctors apply different diagnostic criteria.

It is assumed that, in Europe, around 15 percent of the population suffers from constipation – with twice as many women as men being affected.

Constipation occurs more frequently with advancing age, especially in people over the age of 65. A lack of exercise, being bed-bound and the side-effects of certain medication are possible reasons in some cases.

A person may suffer with constipation for an extended period. Usually, however, the issue resolves and bowel habits return to normal. However, some people have to deal with constipation on an ongoing basis, despite treatment. This can impact their quality of life and lead to complications.

People with chronic constipation often worry that it increases their risk of developing bowel cancer. However, this is not the case.

Among older people in particular, persistent constipation can lead to an accumulation of rock-hard lumps of stool in the intestines known as scybala. The patient may then experience diarrhea with a thin, runny consistency that manages to slide past the scybala. This fecal impaction sometimes requires hospital treatment.

A precise description of bowel habits provides doctors with valuable information when making a diagnosis. Before diagnosing a patient with constipation, doctors will ask for information such as:

• how frequently they have a bowel movement and whether they have difficulty emptying their rectum
• stool shape and consistency
• the patient’s diet and lifestyle
• details of any medication they may be taking

They will also conduct a physical examination, in which they will take a close look at the patient’s anus and examine it with their finger (digital rectal exam).

If this information suggests that the constipation may be caused by an underlying illness, additional tests, such as blood tests, x-rays, ultrasound scans or endoscopies may be needed.

Treatment is often started immediately. If this proves unsuccessful after a period of 4 weeks, additional tests will be considered. In this case, bowel function will be examined using pressure measurements and imaging techniques such as magnetic resonance imaging (MRI).

It has yet to be scientifically proven that testing the stool for bacteria or fungi (known as an “intestinal ecogram”) provides information that doctors can use to determine a course of treatment.

If there is no indication of another health condition that is triggering the constipation, treatment is administered in a phased plan.

Basic measures

Various basic measures are considered first:

• Dietary changes – a fiber-rich diet ensures adequate filling of the intestines so that peristalsis, i.e., muscular contractions of the intestines, can move the intestinal contents along the digestive tract more easily. Fruit, vegetables, wholegrain products and wheat bran are rich in fiber. Bulking agents like psyllium and linseeds or chicory inulin have the same effect. High-fiber fruits like mangoes, plums or kiwis stimulate bowel movements.
• Drink plenty of fluids – the recommended daily fluid intake is 1.5 to 2 liters. An adequate fluid intake is particularly important when consuming a large amount of fiber and bulking agents.
• Movement and exercise – constipation is often associated with a lack of movement and exercise. Age-appropriate physical activity is sufficient to kick-start the healthy movement of food through the digestive tract. This means sitting or lying down as little as possible, going places on foot whenever possible and taking walks. There is generally no benefit to an additional sports program.
• Taking time for bowel movements – constantly suppressing the urge to defecate can cause constipation. It is therefore important to take sufficient time to go to the bathroom when needed.
• Taking digestive supplements – probiotics consist of bacteria that colonize the digestive tract and promote digestion. Prebiotics are nutrients for these bacteria and they bring about an increase in healthy gut flora that promote digestion. Synbiotics combine probiotics and prebiotics. All three types of supplement may increase the frequency of bowel movements and soften the stool. Their effectiveness should be tested over the course of 4 to 6 weeks. The supplement can be stopped once an improvement is seen.

Laxative agents

If the basic measures described above fail to relieve the symptoms, laxative agents may be used.

• Preparations such as Macrogol 4000/PEG 4000 or lactulose draw water into the intestines. This increases stool volume and stimulates the movement of food through the gut.
• Active agents such as bisacodyl/sodium picosulfate or anthraquinones, which occur, for example, in Senna leaves, similarly draw water into the intestines but do also stimulate peristalsis directly. For this reason, they may sometimes cause stomach cramps and diarrhea.

Further measures

If laxatives are unsuccessful or are not well tolerated by a patient and if other measures also fail to produce results, doctors will prescribe prokinetic agents such as prucalopride. These are available in tablet form and stimulate the muscles in the digestive system directly.

If the patient has a primary or accompanying defecation disorder (i.e., a problem with emptying the rectum), defecation aids can be used. An enema is used to introduce water into the bowel through the anus and then remove it, together with the stool. There are also suppositories that stimulate defecation. 

If pelvic floor muscle function is impaired, biofeedback sessions may be beneficial. Some people with constipation find various acupuncture and acupressure techniques helpful.