Common problem beginning with ‘C’

Constipation is one of the most common complaints that people have about their digestive system.
Constipation refers to a disturbance in bowel habits, but it has varied meanings. Stools may be too hard or too small, difficult to pass, or infrequent. Infrequent may be defined as fewer than three spontaneous bowel movements per week. However, the frequent need to strain and a sense that the bowels are not empty after a movement are also acceptable definitions of constipation.

CAUSES - Many factors can contribute to or cause constipation, although in most people no single cause can be found. In general, constipation occurs more frequently as people get older. As many as one-third of all individuals over the age of 65 suffer from constipation. There may be several reasons for this; Older people may have a diet low in fibre, eat too few calories, have decreased physical activity or be using medications that can cause constipation.

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Many medical conditions can also cause constipation. Examples include hypothyroidism (an underactive thyroid), irritable bowel syndrome, diabetes, Parkinson's disease, spinal cord injuries, and colon cancer. In addition, medications used for pain, muscle spasms, depression, mineral deficiencies, high blood pressure and heart disease can often be associated with constipation.

DIAGNOSIS - Initially, a doctor will want to know about a person's bowel habits and the duration of constipation. In many cases, a diary of stool frequency and description is helpful. It is important to discuss any medications that are taken regularly since some can cause constipation.

A clinician may need to perform a rectal examination as part of the physical examination. A rectal examination involves inserting a gloved finger inside the rectum to feel for any lumps or abnormalities. This test can also check for blood in the stool.

Diagnostic testing may be ordered in some situations. These include a recent change in bowel habits, blood in the stool, weight loss, or a family history of colon cancer. Testing can include blood tests, x-rays, sigmoidoscopy, colonoscopy, barium enema, or more specialized testing if needed.

COMPLICATIONS - Constipation is uncomfortable and can interfere with a person's quality of life. In addition, chronic constipation can be associated with other problems, including: Aggravation of haemorrhoids. Fecal impaction (which can cause abdominal pain, nausea, vomiting, urinary retention, and ulcers in the rectum) and anal fissures (painful tears in the anal canal that can be caused by passing a hard stool).

TREATMENT - The most important issues for treating constipation include understanding normal bowel function, eating foods high in fibre, and using laxatives or enemas in an appropriate fashion.
Behaviour changes - The bowels are most active following meals, and this is often the time when stools will pass most readily. When a person ignores his or her body's signals to defecate, the signals become weaker and weaker over time. By paying close attention to these signals, a person may defecate more easily.

Diet - Eating a diet high in fibre is important. The recommended amount of dietary fibre is 20 to 35 grams of fibre per day. Red rice, leaves, legumes, many fruits and vegetables can be particularly helpful in preventing and treating constipation . Some breakfast cereals are also an excellent source of dietary fibre.

In addition, a number of other fibre supplements are available to increase fibre intake. Examples include methylcellulose and wheat dextrin. The dose of fibre supplements should be increased slowly to prevent gas and cramping, and they should always be taken with an extra glass of fluid.

LAXATIVES - A variety of drugs and natural products are available for treating constipation. Because of the large number of options, most have not been directly compared in clinical studies. Thus, the choice between them is based upon their mechanism of action, safety, and experience.

In general, laxatives can be categorized into the following groups:

Bulk forming - These include natural fibre and commercial fibre preparations such as: Psyllium , Methylcellulose and Calcium polycarbophil.

These work by increasing the water content and bulk of stool, which tends to decrease the time needed to pass through the colon.

Hyperosmolar - Hyperosmolar laxatives include: Polyethylene glycol, Lactulose liquid paraffin and Sorbitol.

These reduce water absorption from the colon, thereby wetting the stool. Stools usually become soft, but they are still formed. Lactulose and sorbitol are also digested by bacteria in the colon, which can produce gas and bloating. Sorbitol works as well as lactulose and is much less expensive.

Saline laxatives - Saline laxatives such as magnesium hydroxide and magnesium citrate act similarly to the hyperosmolar laxatives (ie, they draw water into the colon).

Stimulant laxatives - Stimulant laxatives include senna and bisacodyl.

Because of their effectiveness, stimulant laxatives can be overused. Excessive use of stimulant laxatives may be associated with side effects, including low potassium levels. Thus, these drugs should be used with caution if taken regularly. There is no convincing evidence that chronic use of stimulant laxatives causes structural or functional impairment of the colon, nor do they increase the risk for colorectal cancer or other tumours.

Pills, suppositories, or enemas - Laxative preparations are available as pills that are taken by mouth or as suppositories or enemas that are inserted into the rectum. In general, suppositories and enemas work more quickly compared to pills, but many people do not like using them.

Healthcare providers occasionally recommend enemas every three to four days in patients who have not responded to oral laxatives.

BIOFEEDBACK - Biofeedback is a behavioural approach that can be used by some patients with severe chronic constipation. During defecation, the muscles of the pelvic floor and external anal sphincter should relax as a person bears down. Biofeedback can be helpful in treating patients who involuntarily contract (rather than relax) these muscles.

A visual monitor is used to measure external anal sphincter pressures while bearing down. The patient watches the recordings of muscle activity or sphincter pressure responses and is asked to modify inappropriate responses through trial and error. Improvement has been seen in patients with dyssynergic defecation who received biofeedback, and a controlled trial found that it was more effective than laxatives .

WHEN TO SEEK HELP - Patients with constipation should speak with a doctor about their symptoms, especially if the symptoms: are new (ie, represent a change in your normal pattern), last longer than three weeks, are severe, associated with any other worrying features such as blood on the toilet paper, weight loss, fevers, or weakness .

(The writer is Consultant Physician & Gastroenterologist, Sri Lanka Police Hospital, Colombo)