Gastrointestinal System
Vomiting
The lower esophageal sphincter relaxes, allowing the stomach’s
contents to enter the esophagus
The upper esophageal sphincter opens to allow the vomit to be
expelled from the mouth
Diarrhea
Diarrhea occurs when a client has three or more stools with liquid or
loose consistency in a 24-hour period
Acute diarrhea self-resolves in less than 14 days
Chronic diarrhea should be inspected by a specialist
o Weight loss
o Severe malnutrition
o Dehydration
Potential causes of chronic diarrhea:
o Tumors or cancer (adverse effect of related medications)
o Food allergies
o Celiac disease (from malabsorption of nutrients)
o Medication adverse effects
o IBD (causes rapid contractions of the intestinal muscles, leading
to faster bowel movements and decreasing the time for water
absorption)
Infectious agents are the most common cause of acute diarrhea (viral
diseases like norovirus and rotavirus)
Antibiotics can imbalance the flora in the intestinal tract, causing C.
diff
Vibrio cholerae or E. Coli are the most common bacterial infections
that lead to diarrhea
Shigella is the most common cause of bloody and persistent diarrhea
Stool culture: identify parasites and bacterial infections. Typically for
clients who have blood in the stool or have a fever
Rotavirus antigen test: test for rotavirus in the stool; not necessary
unless there is an outbreak
Stool occult blood: detects active bleeding in the stool. This can occur
because of underlying diseases like Shigella or Salmonella
CBC with differential: determines the presence of infection.
CMP, Chem 8 or Chem 20: checks electrolyte levels to determine
dehydration. Checks kidney function through BUN and creatinine
Urine-specific gravity: assess for dehydration
Chronic diarrhea from illnesses such as Crohn’s disease can cause
delayed puberty or delayed sexual development
Constipation
Experiencing less than 2 bowel movements per week or having painful
or difficult bowel movements
Consistent constipation can cause a fecal impaction
This study source was downloaded by 100000903111493 from CourseHero.com on 03-06-2026 10:11:24 GMT -06:00
https://www.coursehero.com/file/254248646/ATI-Exam-4-1docx/
, Children who are constipated can have fecal incontinence
Constipation for infants and children:
o Excess water absorption in the colon causes stool to be hard and
dry
o Slowed colonic motility decreases peristalsis resulting in longer
transit time
o Impaired rectal sensation and coordination weaken the urge to
defecate
o Impaired anal sphincter or intestinal muscle coordination
causes problems with initiating or completing bowel movements
Constipation complications:
o Feal impaction
o Fecal incontinence
o Anal fissures
o Rectal prolapse
o UTIs
o Megacolon
Barium enema x-ray: contrast (barium) is inserted into the rectum to
assess the structure and function of the colon
Colonic transit study: client ingests markers that are monitored
through a series of x-rays. It measures the time it takes for food to
move through the large intestine.
Anorectal manometry: measures pressure changes during rectal
distention and relaxation to evaluate the coordination of rectal and
anal sphincters
MRI: rule out unexpected findings in the lumbosacral spine (LSS)
Dehydration
Isotonic dehydration: water and sodium are lost together; usually
because of diarrhea and vomiting. Blood sodium is typically within
expected limits
Hypotonic dehydration: sodium loss is greater than water loss.
Typically caused by endocrine issues, diuretics or cystic fibrosis.
Blood sodium is less than 130 mEq/L
Hypertonic dehydration: water loss exceeds sodium secretion.
Typically because of fever. Blood sodium is greater than 145 mEq/L
Signs of dehydration:
o Decreased level of consciousness (lethargic)
o Breathing difficulties (severe respiratory distress or not
breathing)
o Skin color (mottled, gray or cyanotic)
Causes:
o Not drinking enough water
o Poor feeding
This study source was downloaded by 100000903111493 from CourseHero.com on 03-06-2026 10:11:24 GMT -06:00
https://www.coursehero.com/file/254248646/ATI-Exam-4-1docx/
Vomiting
The lower esophageal sphincter relaxes, allowing the stomach’s
contents to enter the esophagus
The upper esophageal sphincter opens to allow the vomit to be
expelled from the mouth
Diarrhea
Diarrhea occurs when a client has three or more stools with liquid or
loose consistency in a 24-hour period
Acute diarrhea self-resolves in less than 14 days
Chronic diarrhea should be inspected by a specialist
o Weight loss
o Severe malnutrition
o Dehydration
Potential causes of chronic diarrhea:
o Tumors or cancer (adverse effect of related medications)
o Food allergies
o Celiac disease (from malabsorption of nutrients)
o Medication adverse effects
o IBD (causes rapid contractions of the intestinal muscles, leading
to faster bowel movements and decreasing the time for water
absorption)
Infectious agents are the most common cause of acute diarrhea (viral
diseases like norovirus and rotavirus)
Antibiotics can imbalance the flora in the intestinal tract, causing C.
diff
Vibrio cholerae or E. Coli are the most common bacterial infections
that lead to diarrhea
Shigella is the most common cause of bloody and persistent diarrhea
Stool culture: identify parasites and bacterial infections. Typically for
clients who have blood in the stool or have a fever
Rotavirus antigen test: test for rotavirus in the stool; not necessary
unless there is an outbreak
Stool occult blood: detects active bleeding in the stool. This can occur
because of underlying diseases like Shigella or Salmonella
CBC with differential: determines the presence of infection.
CMP, Chem 8 or Chem 20: checks electrolyte levels to determine
dehydration. Checks kidney function through BUN and creatinine
Urine-specific gravity: assess for dehydration
Chronic diarrhea from illnesses such as Crohn’s disease can cause
delayed puberty or delayed sexual development
Constipation
Experiencing less than 2 bowel movements per week or having painful
or difficult bowel movements
Consistent constipation can cause a fecal impaction
This study source was downloaded by 100000903111493 from CourseHero.com on 03-06-2026 10:11:24 GMT -06:00
https://www.coursehero.com/file/254248646/ATI-Exam-4-1docx/
, Children who are constipated can have fecal incontinence
Constipation for infants and children:
o Excess water absorption in the colon causes stool to be hard and
dry
o Slowed colonic motility decreases peristalsis resulting in longer
transit time
o Impaired rectal sensation and coordination weaken the urge to
defecate
o Impaired anal sphincter or intestinal muscle coordination
causes problems with initiating or completing bowel movements
Constipation complications:
o Feal impaction
o Fecal incontinence
o Anal fissures
o Rectal prolapse
o UTIs
o Megacolon
Barium enema x-ray: contrast (barium) is inserted into the rectum to
assess the structure and function of the colon
Colonic transit study: client ingests markers that are monitored
through a series of x-rays. It measures the time it takes for food to
move through the large intestine.
Anorectal manometry: measures pressure changes during rectal
distention and relaxation to evaluate the coordination of rectal and
anal sphincters
MRI: rule out unexpected findings in the lumbosacral spine (LSS)
Dehydration
Isotonic dehydration: water and sodium are lost together; usually
because of diarrhea and vomiting. Blood sodium is typically within
expected limits
Hypotonic dehydration: sodium loss is greater than water loss.
Typically caused by endocrine issues, diuretics or cystic fibrosis.
Blood sodium is less than 130 mEq/L
Hypertonic dehydration: water loss exceeds sodium secretion.
Typically because of fever. Blood sodium is greater than 145 mEq/L
Signs of dehydration:
o Decreased level of consciousness (lethargic)
o Breathing difficulties (severe respiratory distress or not
breathing)
o Skin color (mottled, gray or cyanotic)
Causes:
o Not drinking enough water
o Poor feeding
This study source was downloaded by 100000903111493 from CourseHero.com on 03-06-2026 10:11:24 GMT -06:00
https://www.coursehero.com/file/254248646/ATI-Exam-4-1docx/
