Bowel Elimination
Dr. Belal Hijji, RN, PhD
March 10 & 17, 2012
Learning Outcomes
After this lecture, students will be able to:
• Describe the anatomy and physiology of the GIT
• Identify common bowel elimination problems and factors
influencing elimination
• Describe factors affecting bowel elimination
• Discuss nursing assessment and diagnostic tests.
• Discuss nursing interventions for selected alterations in bowel
function.
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Anatomy and Physiology of the GIT
• Mouth: The mouth mechanically and chemically breaks down
nutrients into usable size and form. Digestion begins in the
mouth and ends in the small intestine.
• Oesophagus: As food enters the upper esophagus, it passes
through the upper oesophageal sphincter. This sphincter is a
circular muscle that prevents air from entering the esophagus
and food from refluxing into the throat.
• Stomach: Has three functions: the storage of swallowed food
and liquid; mixing of food, liquid, and digestive juices; and
emptying its contents into the small intestine. The stomach
produces and secretes hydrochloric acid (HCL), mucus
[protective], pepsin, and intrinsic factor [for absorption of
vitamin B12).
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• Small intestine: Is divided into the duodenum [2 feet], the
jejunum [9 feet], and the ileum [12 feet]. Most nutrients and
electrolytes are absorbed in the small intestine.
• Large intestine (lower GIT): Is divided into the cecum, colon,
and rectum. The colon has three tasks: absorption, secretion,
and elimination.
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• Anus: Is the place where feces is expelled out of the body. The
anal canal is richly supplied with sensory nerves that help to
control continence.
• Defecation: The physiological factors critical to bowel
function and defecation include normal GIT function, sensory
awareness of rectal distension and rectal contents, voluntary
sphincter control, and adequate rectal capacity and compliance
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Common Bowel Elimination Problems
• Constipation: Constipation is the infrequent and difficult
passage of hardened stool. Constipation can be caused by
certain medications (ie, antidepressants, antihypertensives,
opioids, antacids with aluminum, and iron); rectal or anal
disorders (eg, hemorrhoids, fissures); obstruction (eg, cancer
of the bowel); metabolic and neuromuscular conditions (eg,
diabetes mellitus, multiple sclerosis); and endocrine disorders
(eg, hypothyroidism, pheochromocytoma). Other causes
include weakness, immobility, and an inability to increase
intra-abdominal pressure to facilitate the passage of stools.
Constipation results from dietary habits (ie, low consumption
of fiber and inadequate fluid intake), lack of regular exercise,
and a stress-filled life.
• Impaction: Results from unrelieved constipation, whereby
hardened faeces cannot be expelled for several days despite
repeated urge to defecate. Impaction develops in patients who
are unconscious, badly constipated, or those with interrupted
nerve supply to bowel.
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• Diarrhea: Is an increased frequency in the passage of loose
stools which may lead to fluid and electrolyte imbalance.
Causes of diarrhea include infectious agents (Clostridium
difficile, Escherichia coli, Salmonella, Shigella, Entamoeba
histolytica, and Giardia), inflammatory bowel disease, short
bowel syndrome (due to reduced surface area for
reabsorption), side effects of drugs (multiple antimicrobial
agents can promoting an overgrowth of C. difficile in the
bowel; and laxative or enema misuse).Intestinal contents are
irritating and can lead to skin breakdown in the perianal
region. The aim of treating diarrhea is to maintain adequate
hydration and electrolyte balance.
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• Incontinence: Fecal incontinence is the involuntary loss of
stool of sufficient magnitude to create a social or hygienic
problem. When impaction of stool develops, bacteria in the
rectum overgrow, producing a liquefied stool. The toxins
produced by this medium can stimulate the bowel and may
produce transient seepage of stool in the normally continent
client. Sensory disorders interferes with the client’s ability to
differentiate gas and solid and liquid contents in the rectum.
Anatomic disorders also may compromise sphincter function.
Women are at risk for obstetric trauma. Vaginal deliveries,
requiring the use of forceps, are likely to damage the anal
sphincter mechanism.
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Factors Influencing Bowel Elimination
• Age: Ability to control defecation occurs at the age of 2-3
years. In older adults, peristalsis declines, esophageal
emptying slows. Muscle tone in the perianal floor and anal
sphincter weakens, causing difficulty in controlling defecation.
• Diet: Regular daily food intake, high-fiber foods, raw or
cooked fruits, vegetables, and cereals and bread promote
peristalsis. Low-fiber foods (lean meats, milk) slow peristalsis.
Gas producing foods (broccoli, cauliflower, onions, dried
beans) can stimulate peristalsis.
• Position during defecation: Squatting allows a person to lean
forward, exert intraabdominal pressure, and contract thigh
muscles to normally defecate. Immobilised client using a
bedpan cannot contract muscles to defecate.
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• Pregnancy: Pressure adds to the rectum leading to
constipation.
• Diagnostic tests: Examination of the GIT structures require
emptying of bowel contents. NPO status, bowel evacuants, and
cleansing enemas are factors that interfere with normal
elimination.
• Fluid intake: Water liquefies intestinal contents for easier
passage. Hot beverages and fruit juices soften stool and
increase peristalsis. Large quantities of milk may slow
peristalsis and cause constipation.
• Activity: immobilisation depresses colon motility and regular
physical exercise promotes peristalsis.
• Psychological factors: Anxiety or fear can accelerate digestion
and peristalsis. Diarrhea may result.
• Pain: Can suppress defecation resulting in constipation.
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Assessment
• Health history: Because issues of elimination may produce
feelings of anxiety, guilt, or shame among clients, the
interview must be instigated by the nurse and conducted in a
setting that provides adequate privacy. The nurse should ask
clients to describe their usual elimination habits, the nature of
the current problem and its duration, the types of food that
cause diarrhea, and identify the bowel management
programme such as how bowel is evacuated, regular use of
laxatives, suppositories, or enemas).
• Physical exam: Mental status can be evaluated by listening to
the client’s responses to questions and by observing
interactions with others.
Continued…
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• Physical exam (continued…): The nurses should assess
mobility and dexterity. Mobility may be evaluated by
observing the client undress or move onto a table, chair, or
bed. Dexterity [skill] is assessed by observing the client
remove clothing; particular attention is paid to the
manipulation of zippers, buttons, and shoestrings. The
perineum is initially inspected for skin integrity. Among
patients with severe fecal incontinence, the skin is frequently
red and painful to touch, due to exposure to liquid stool. The
integrity of the skin typically remains intact with mild to
moderate fecal incontinence.
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Diagnostic and Laboratory Data
• A stool culture for ova and parasites, electrolytes, or when
gastrointestinal infection is thought to be causing diarrhea and
related incontinence.
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Planning
•
•
•
•
•
Maintain elimination health
Initiate exercise regimen
Initiate diet and fluid therapy
Administer medications
Administer enema
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Maintaining Elimination Health
• Fluid intake: Clients should be taught to drink an adequate
amount of fluid each day, which is 30 ml/kg body weight. In
the average-sized adult, this equals 1500 to 2000 ml/d.
• Diet: Dietary fiber may prevent constipation and increase the
desire to defecate. The client is taught to increase gradually the
amount of fiber-rich foods in the diet, including grains, fruits,
and vegetables.
• Lifestyle and prevention: Smoking stimulates the bowel
causing increased bowel tone and motility, resulting in
diarrhea. Acute and chronic stress affect bowel by increasing
its activity. Managing stress promotes healthy bowel
elimination patterns. Nurses are in position to educate clients
on how to manage stress (This will be discussed later).
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• Elimination habits: The client is urged to establish a regular
schedule of bowel elimination and to answer the desire to
defecate, as routine avoidance may predispose to constipation
and reduce the efficiency of bowel evacuation. The urge to
defecate is typically greatest after a meal, and it may be
enhanced by dietary stimulants such as fiber or a caffeinated
beverage or by light exercise.
• Positioning: Positioning of the client plays an important role in
elimination. Sitting is the usual position for a client for bowel
elimination. Clients unable to use the toilet require assistance
in accomplishing elimination. Devices such as the bedpan or
commode can be used
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Initiate Exercise Regimen
• Regular exercise leads to good muscle tone and stimulates the
bowels to move regularly.
• Inadequate tone in the abdominal muscles, diaphragm, and the
perineal muscles can cause difficult defecation. If a client is
suffering from constipation, a regimen of walking or light
recreational exercise should be recommended to promote
peristalsis and defecation.
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Initiating Diet and Fluid Therapy
• Dietary fiber and fluid intake can be increased to promote the
passage of soft, hydrated stool. The client who is unable or
unwilling to obtain adequate fiber from the diet may be given a
bulk laxative (such as Metamucil) or a bran mixture as a
specific dietary supplement. Initially, 3 to 6 grams of the
supplement is administered, and the dosage is gradually
increased until a soft, well-formed stool is obtained.
• The initial management of diarrhea involves the removal of
factors that predispose the individual to the condition and the
maintenance of adequate fluid and electrolyte balance. Persons
with infectious diarrhea are given antimicrobials to destroy the
pathogens that produce diarrhea.
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Administering Medications
• Constipation is initially managed by assisting the individual to
pass hardened stool or by removing any impacted feces. Bowel
evacuation is encouraged by an oral laxative, such as psyllium.
• Constipation resulting in an impaction requires mechanical
disruption and removal, followed by a cleansing enema or an
oral laxative. Alternatively, a pulsed irrigation enhanced
evacuation (PIEE) system can be used. The PIEE uses gravity
to deliver intermittent pulses of warmed saline to break up and
remove hardened and impacting fecal material.
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Administering Enema
• Enema administration is a procedure used to introduce fluid
into the lower bowel. The purpose of an enema is to cleanse
the lower bowel, to assist in the evacuation of stool or flatus,
or to instill medication. See next slide for the types of enemas,
along with the solutions and the indications for use of each.
• Enemas can be large (500 to 1000 ml) or small (150 to 240 ml)
depending on their purpose. Large-volume enemas are
administered to cleanse the bowel. Small-volume enemas are
used for the purpose of evacuating stool or instilling
medications in the lower bowel. Caution should be used when
administering large volume enemas, because fluid and
electrolyte imbalance can occur.
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Types of Enemas
Type
Cleansing
Solution
Tap water
Soap suds
Normal saline
Retention
Emollient
(oil)
Carminative
Tap water
{gas expulsion} Normal saline
Indications
Evacuate lower bowel
before diagnostic studies
or surgery
Soften and lubricate stool
for easy evacuation
Relief of distension due to
flatus
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