SOAP. – Constipation

Definition

A.Constipation means infrequent and difficult defecation of hard stools and a sensation of incomplete evacuation or straining. Constipation may also refer to a decrease in the volume or weight of stool, and the need for enemas, suppositories, or laxatives to maintain bowel regularity. Constipation is a symptom, not a disease.

B.The lower limit of normal stool frequency is three bowel movements (BMs) a week. The Rome consensus criterion defines constipation as two or more of the following occurring over a period of 3 months: two or fewer stools weekly, sensation of straining, sensation of incomplete evacuation or sensation of obstruction or blockage, and/or the need for digital removal of stool.

C.Classification of constipation includes the following:

1.Primary constipation:

a.Normal-transit constipation (most common).

b.Functional constipation (slow transit).

c.Defecatory disorders.

2.Secondary constipation:

a.Dietary deficiency.

b.Structural obstruction.

c.Systemic—related to endocrine, neurologic, or connective tissue disorder.

Incidence

A.The incidence of constipation is 16% among all adults and 33% in patients greater than 60. Constipation is commonly self-reported. Constipation occurs in more than 50% of patients with colorectal cancer (CRC); it is usually a symptom of advanced disease, but it may be the presenting complaint.

Pathogenesis

A.Constipation can be caused by an alteration of the filling of the rectum by colonic transportation and/or reflex defecation of stool.

B.Lack of exercise and prolonged bed rest decreases propulsion of bowel contents.

C.During pregnancy, progesterone has a relaxing effect on the muscles of the gastrointestinal (GI) tract and causes a decrease in peristalsis. The compression of the intestines by the enlarging uterus causes constipation during pregnancy.

D.Habitual use of laxatives is associated with impaired colonic motor activity and has the potential of producing hypokalemia.

TABLE 14.4 Drugs and Classifications That Cause and Increase Constipation

NSAIDs, nonsteroidal anti-inflammatory drugs; MAOIs, monoamine oxidase inhibitors.

E.Hypokalemia can produce a generalized ileus and is most often seen in patients who take diuretics.

F.Psychiatric disease and psychosocial distress have important roles. The exact mechanisms by which emotional difficulties lead to constipation remain unclear, but their contribution is widely recognized.

G.Drugs (see Table 14.4).

Predisposing Factors

A.Insufficient nutrition:

1.Low-fiber diet.

2.Low fluid intake.

B.Neurologic causes:

1.Spinal cord injury.

2.Parkinson’s disease.

3.Multiple sclerosis.

4.Aganglionosis (Hirschsprung’s disease).

5.Sacral nerve trauma/tumor.

C.Sedentary lifestyle/impaired mobility.

D.Laxative abuse.

E.Travel.

F.Ignoring urge to defecate.

G.Drug use (individual medications and polypharmacy).

H.Pregnancy, especially third trimester.

I.Psychosocial problems:

1.Depression.

2.Sexual abuse.

3.Unusual attitudes to food and bowel function.

4.Obsessive/compulsive.

J.Extremes of ages: Infants and geriatrics.

K.Hypothyroidism.

L.CRC.

M.irritable bowel syndrome (IBS).

N.Pelvic floor disorders:

1.Impaired function of the pelvic floor and/or external sphincter.

2.Pelvic floor obstruction.

3.Rectal prolapse.

4.Enterocele and/or rectocele.

5.Rectal intussusception.

Common Complaints

A.Hard, infrequent stools.

B.Straining.

C.Inability to defecate when desired.

D.Need for digital manipulation to facilitate evacuation.

Other Signs and Symptoms

A.Hard, pebbly, rocklike stools.

B.Painful defecation.

C.Abdominal pain/distention.

D.Weight loss.

E.Blood in stools.

Potential Complications

A.A rectal prolapse of the mucosa is pink and looks like a doughnut or rosette. Complete prolapse involving the muscular wall is larger and red, and it has circular folds.

B.Anal fissure.

C.Hemorrhoidal disease.

D.Pelvic floor damage in women.

E.Rectal ulceration.

F.Fecal impaction.

G.Bowel obstruction.

H.Fecal incontinence (FI).

I.Megacolon.

J.Volvulus.

K.Urinary retention.

L.Syncope.

M.Anal fistula.

Subjective Data

A.Review the onset, duration, and course of symptoms:

1.Is constipation a chronic or acute problem?

2.If there has been a change in bowel habits, was it gradual or sudden?

3.What feature does the patient rate most distressing?

B.Review bowel habits:

1.Does the patient have a regular time for defecation?

2.Review size, color, consistency, and frequency of stools.

3.Is there any blood?

4.Are there any periods of diarrhea?

5.How often are laxatives being used, and what doses?

6.Are suppositories and enemas also required?

7.Does the patient have the urge to defecate?

8.Does the patient have a sensation of incomplete evacuation?

9.Does the patient need to digitally remove stool?

C.Review the patient’s daily diet and fluid intake. Has there been any dietary change?

D.Review the patient’s medication history: prescription and over-the-counter (OTC; refer to Table 14.4).

E.Review the patient’s daily physical activity.

F.Review the patient’s psychosocial history of stress, depression, anxiety, and coping mechanisms.

G.Review the patient’s other health problems such as diabetes, depression, hypothyroidism, and hypercalcemia.

H.Review family history of constipation and CRC.

I.Review surgical history.

Physical Examination

A.Check pulse, respirations, blood pressure (BP), and weight. Check temperature if indicated.

B.Inspect:

1.General overall assessment of nutritional status.

2.Examine the skin for pallor and signs of dehydration and hypothyroidism.

3.Evaluate for the presence of hernias.

4.Inspect anus, including the position, presence of perianal erythema, hemorrhoids, and skin tags.

5.Observe for signs of fecal soiling.

6.Examine the lower back to rule out spinal lesions—hairy or hyperpigmented patches, gluteal fold asymmetry, cutaneous dimples, sinus tracts, and lipomas.

7.The American Gastroenterology Association (AGA) notes that the patient should be in the left lateral position with the buttocks separated to evaluate:

a.Observe the descent of the perineum during simulated bowel evacuation.

b.Observe the elevation during a squeeze aimed at retention of stool.

c.During the simulated defecation, the anal verge should be observed for any patulous opening or prolapse of anorectal mucosa.

C.Auscultate: Auscultate abdomen for bowel sounds. Auscultation of the abdomen should precede any palpation or percussion due to the changes in intensity and frequency of sounds after manipulation. Bowel sounds may be high pitched or absent in the presence of constipation.

D.Percuss: Percuss the abdomen.

E.Palpate:

1.Palpate the abdomen for masses, tenderness, distension, and fecal mass.

2.Palpate the liver and spleen.

F.Digital rectal exam:

1.Examine the rectum for masses, hemorrhoids, fissures, fistula, prolapse, inflammation, and anal warts.

2.Evaluate for impaction, hard stool in ampulla.

3.Perform an anal wink reflex test by a light pinprick or scratch.

4.Evaluate sphincter tone:

a.Disordered innervation of the anus is indicated by finding that the anal canal opens wide when the puborectalis muscle is pulled posteriorly.

b.Evaluate the resting tone of the sphincter and squeezing effort.

c.Instruct the patient to expel the examination finger to evaluate the force of expulsion.

G.Perform a neurologic examination for tone, strength, and reflexes to search for focal deficits and delayed relaxation phase of the ankle jerks, suggestive of hypothyroidism.

H.Perform pelvic examination to evaluate a prolapse or rectocele. Evaluate when the patient is at rest and with straining.

I.Perform mental status examination, checking for signs of depression and somatization.

Diagnostic Studies

A.No tests are required for the diagnosis of chronic constipation.

B.Because laboratory tests have demonstrated low sensitivity for indicating a cause for constipation, unless there are alarm symptoms (as defined as follows), initial treatment may consist of alterations in the diet and activity level, and addition of laxatives.

Alarm symptoms:

1.Weight loss of greater than 10 lbs.

2.Rectal bleeding or positive test for occult blood.

3.Abdominal pain.

4.Inability to pass flatus.

5.Vomiting.

6.Change in bowel habits in a patient older than 50 years.

7.Positive family history of CRC or inflammatory bowel disease (IBD).

C.If a trial of lifestyle modifications and/or laxatives is unsuccessful, further investigation is warranted.

D.Laboratory tests:

1.Complete blood count (CBC).

2.Thyroid studies.

3.Potassium and calcium. Patients taking diuretics should have serum potassium checked. Hypokalemia may reduce bowel contractility and produce an ileus.

4.Serum glucose to rule out diabetes.

5.Stool for occult blood.

E.Radiographs:

1.Plain abdominal radiographs may be useful to evaluate stool burden and assess for obstruction or megacolon.