Friday, March 29, 2024

Constipation

Practice Essentials

Constipation is a symptom rather than a disease, generally defined as when bowel movements occur three or fewer times a week and are difficult to pass.
It is the one of the most common digestive complaints in the United States
in ambulatory centers and a common cause for referral to gastroenterologists and colorectal surgeons.
 Despite its frequency, it often remains unrecognized until the patient develops sequelae, such as anorectal disorders. (See the image below.)

Constipation. Note the large amount of stool throu

Constipation. Note the large amount of stool throughout the colon on this radiograph.

View Media Gallery

Signs and symptoms

According to the Rome IV criteria for constipation, a patient must have experienced at least two of the following symptoms over the preceding 6 months:

Fewer than three spontaneous bowel movements per week

Straining for more than 25% of defecation attempts

Lumpy or hard stools for at least 25% of defecation attempts

Sensation of anorectal obstruction or blockage for at least 25% of defecation attempts

Sensation of incomplete defecation for at least 25% of defecation attempts

Manual maneuvering required to defecate for at least 25% of defecation attempts

In addition, the patient must rarely have loose stools present without use of a laxative and must not meet Rome IV criteria for irritable bowel syndrome (IBS).

A constipated patient may be otherwise totally asymptomatic or may complain of one or more of the following:

Abdominal bloating

Pain on defecation

Rectal bleeding

Spurious diarrhea

Low back pain

The following also suggest that the patient may have difficult rectal evacuation:

Feeling of incomplete evacuation

Digital extraction

Tenesmus

Enema retention

The following signs and symptoms, if present, are grounds for particular concern:

Rectal bleeding

Abdominal pain (suggestive of possible IBS with constipation [IBS-C])

Inability to pass flatus

Vomiting

See Presentation for more detail.

Diagnosis

An extensive workup of the constipated patient is performed on an outpatient basis and usually occurs after approximately 3-6 months of failed medical management. Anorectal tests should be used to evaluate for defecatory disorders if over-the-counter agents do not relieve the constipation.

Features of the workup are as follows:

Rectal and perineal examination should already have been performed but should be repeated

Laboratory evaluation does not play a large role in the initial assessment of the patient

Imaging studies are used to rule out acute processes that may be causing colonic ileus or to evaluate causes of chronic constipation

In patients with acute abdominal pain, fever, leukocytosis, or other symptoms suggesting possible systemic or intra-abdominal processes, imaging studies are used to rule out sources of sepsis or intra-abdominal problems

Lower gastrointestinal (GI) endoscopy, colonic transit study, defecography, anorectal manometry, surface anal electromyography (EMG), and balloon expulsion testing may be used in the evaluation of constipation

See Workup for more detail.

Management

Initial treatment measures for constipation include manual disimpaction and transrectal enemas. A well-lubricated gloved finger might be required in patients with lower anorectal impactions. These initial measures are then followed by elective evaluation of the causes of constipation.

Medical care should focus on dietary changes and exercise rather than laxatives, enemas, and suppositories, none of which really address the underlying problem.

The key to treating most patients with constipation is correction of dietary deficiencies, which generally involves increasing intake of fiber and fluid and decreasing the use of constipating agents (eg, milk products, coffee, tea, alcohol).

Medications to treat constipation include the following:

Bulk-forming agents (fibers; eg, psyllium): arguably the best and least expensive medication for long-term treatment

Emollient stool softeners (eg, docusate): Best used for short-term prophylaxis (eg, postoperative)

Rapidly acting lubricants (eg, mineral oil): Used for acute or subacute management of constipation

Prokinetics (eg, tegaserod): Proposed for use with severe constipation-predominant symptoms

Stimulant laxatives (eg, senna): Over-the-counter agents commonly but inappropriately used for long-term treatment of constipation

Newer therapies for constipation include the following:

Prucalopride is a prokinetic selective 5-hydroxytryptamine-4 (5-HT4) receptor agonist that stimulates colonic motility and decreases the transit time

The osmotic agent lubiprostone is FDA approved for constipation caused by IBS
and opioid-induced constipation
in adults with chronic, noncancer pain

Another osmotic laxative is lactitol, which is indicated for adults with chronic idiopathic constipation (CIC)

Linaclotide
and plecanatide
are guanylate cyclase C (GC-C) agonists; they are indicated for chronic idiopathic constipation. Additionally, linaclotide is indicated for constipation caused by IBS in adults

Several peripherally-acting mu-opioid receptor antagonists (PAMORA) have been approved by the FDA for opioid-induced constipation in adults with chronic noncancer pain and/or for palliative care (eg, naloxegol, methylnaltrexone, naldemedine)

See Treatment and Medication for more detail.

Previous articleAbdominal Abscess
Next articleAsystole
RELATED ARTICLES
- Advertisment -

Most Popular