Constipation and diarrhea Flashcards
What is the definition of acute diarrheal illness according to the WHO?
The passage of three or more liquid or watery stools in a 24-hour period, for a duration of up to 14 days.
This definition highlights the distinction between true diarrhea and complaints of more frequent but formed stools.
What were Hippocrates’ views on diarrhea?
Diarrhea was understood as a symptom of various diseases, both infectious and noninfectious, and could be caused by faulty food handling or inadequate hygiene practices.
How is diarrhea categorized based on severity?
Diarrhea may be characterized as mild, moderate, or severe based on:
* Accompanying symptoms
* Presence of comorbidities
* Degree of incapacitating dehydration
* Need for hospitalization.
What are common demographics at risk for diarrheal illness?
Children younger than 5 years and adults older than 65 years, or those who are immunocompromised.
What is severe acute diarrhea?
An acute diarrheal episode requiring hospital admission, associated with significant fluid losses and potentially life-threatening, especially in vulnerable populations.
What factors can lead to acute diarrhea in HIV patients?
Impaired enteric defenses in intestinal mucosa due to lymphocyte depletion, particularly with CD4 counts less than 200.
What foods are commonly associated with acquiring diarrheal illness?
Foods such as:
* Raw or undercooked fish
* Shellfish
* Meat
* Eggs
* Unpasteurized dairy products
* Contaminated raw produce.
What percentage of travelers from developed to developing countries acquire acute diarrhea?
Up to 60%.
What is dysentery?
Infectious diarrhea in which enteropathogens invade the intestinal mucosa, resulting in fever, abdominal pain, and visible blood mixed with stools.
What are key historical features to note in a patient presenting with diarrhea?
Onset and duration of symptoms, character of stools, fever, abdominal pain, nausea, vomiting, ability to maintain oral hydration, and dietary history.
How can diarrheal illness be categorized?
Diarrheal illness may be divided into:
* Infectious
* Noninfectious.
What are common viral agents identified in hospitalized patients with acute diarrhea?
Norovirus, rotavirus, and adenovirus.
What bacterial pathogens are frequently associated with acute diarrhea?
Common pathogens include:
* Campylobacter spp.
* Clostridioides difficile
* Various pathogenic Escherichia coli
* Salmonella spp.
* Shigella spp.
* Yersinia enterocolitica.
What is the association between E. coli O157:H7 and health conditions?
It is associated with hemolytic uremic syndrome.
What is Vibrio cholera known for?
Associated with contaminated water or seafood, leading to profuse watery diarrhea and significant fluid and electrolyte loss.
What parasitic infection can lead to both acute and chronic diarrhea?
Giardia lamblia.
Fill in the blank: Runners diarrhea is described as an acute exercise-related diarrhea which may have multiple causes, including _______.
Transient mesenteric ischemia.
What are some noninfectious causes of diarrhea?
Noninfectious causes include:
* Foods (sorbitol, xylitol)
* Pharmaceuticals (laxatives, chemotherapeutic agents)
* Endocrinopathies.
Describe Bristol Stool Scale
Common Causative agents of Acute Infectious diarrhea
Causes of Non infectious diarrhea
What is the initial assessment focus for a patient with diarrhea?
Ensuring clinical stability with attention to volume status.
This includes checking for signs of hypovolemia and hypoperfusion.
List indications of hypovolemia and hypoperfusion.
- Tachycardia
- Hypotension
- Dry mucosa
- Cool extremities
- Diaphoresis
- Poor skin turgor
- Decreased urine output
- Mental status changes
What respiratory signs may indicate an associated acid-base disorder?
Increased respiratory rate or Kussmaul respirations.
Kussmaul respirations are typically deep, labored breaths.
Why might heart rate be an unreliable indicator of volume status in certain patients?
Patients taking antiarrhythmic medications or those reliant on a pacemaker may have unreliable heart rate readings.
What are some clinical signs of dehydration in pediatric patients?
- Sunken eyes
- Depression of the fontanel
- Reduced number of wet diapers
- Decrease in energy, alertness, or activity
What should be assessed in the secondary evaluation of a patient with diarrhea?
The patient’s overall health condition, including the presence of fever and potential for an acute abdomen.
What can focal abdominal pain in the setting of diarrhea indicate?
It may mimic an acute surgical abdomen.
What findings can a rectal examination reveal?
- Melena
- Hematochezia
- Fecal impaction
What does the presence of gross blood in stools indicate?
It may indicate invasive, infectious diarrhea or other pathologic states manifesting with gastrointestinal bleeding.
What systemic findings may demonstrate associated liver pathology?
- Jaundice
- Scleral icterus
What are some clinical presentations of toxic syndromes that may include diarrhea?
- Anticholinergic syndromes
- Sympathomimetic syndromes
When is laboratory testing not necessary in cases of acute diarrhea?
When the clinical severity of the illness is low, including stable vital signs and absence of serious intra-abdominal disease.
What laboratory findings may prompt further investigation in cases of acute diarrhea?
- Toxic appearance with fever
- Moderate-to-severe volume depletion
- Blood- or mucus-containing stools
- Serious comorbidities
What is leukocytosis associated with?
C. difficile infections.
What blood tests may be useful in assessing patients with acute diarrhea?
- Hemoglobin levels
- Basic metabolic panel
- Liver function tests
What is the significance of a positive stool guaiac test?
It should not be used in isolation to guide antibiotic therapy.
What are the typical tests for specific pathogens in acute diarrhea?
Stool cultures, PCR testing, and specific assays for pathogens like C. difficile and E. coli O157:H7.
What factors may prompt testing for Clostridioides difficile?
- Immunocompromised status
- Recent antibiotic use
- Significant diarrhea (>5/day)
What assay is the choice for diagnosing C. difficile infection?
Quantitative PCR.
What should be considered when testing for Escherichia coli O157:H7?
Known outbreaks or presentations in endemic areas.
What tests are useful for patients with chronic diarrhea?
- Stool examination for ova and parasites
- Giardia antigen assay
- Serologic testing for amebiasis
When are radiographic studies indicated in the evaluation of acute diarrhea?
If peritoneal signs are present or abdominal perforation is suspected.
What imaging modality is typically chosen for suspected abdominal perforation?
Abdominal computed tomography (CT) scan with intravenous contrast.
Diagnostic algorithm of diarrhea
When should patients with diarrhea be referred to a gastroenterologist?
Patients with diarrhea concerning for inflammatory bowel disease or other chronic gastrointestinal conditions
Referral is for further diagnostic testing, including endoscopy, biopsy, or other stool studies.
What factors are critical in diagnosing patients with diarrhea?
Effects of diarrhea and patient comorbidity
This includes hypovolemia, renal compromise, immune compromise, advanced age, and inflammatory bowel disease.
What should be evaluated in patients with diarrhea accompanied by abnormal vital signs?
Shock
Resuscitation, including IV fluids, is essential while investigating the underlying etiology of shock.
What laboratory studies may be included in the evaluation of diarrhea?
- Creatinine to assess renal status
- Hemoglobin to assess for gastrointestinal bleeding or hemoconcentration
- Lactate to assess for organ perfusion
- White blood cell count for infection assessment
Elevated white blood cell count can be nonspecific.
Which populations are at particular risk for shock due to diarrhea?
- Elderly
- Pediatric populations
- Immunocompromised individuals
These groups may experience more severe complications from diarrhea.
What is the initial management for mild fluid losses due to diarrhea?
Oral rehydration
This can include sports beverages, commercial rehydration solutions, or a balanced clear liquid diet.
What is the WHO’s oral rehydration solution formula?
Dissolve in 1 L of clean water: * 3.5 g sodium chloride * 2.9 g trisodium citrate or 2.5 g sodium bicarbonate * 1.5 g potassium chloride * 20 g glucose or 40 g sucrose
This solution is used for rehydration in cases of diarrhea.
What dietary recommendations are made for patients with diarrhea?
- Avoid caffeine
- Avoid high-fat foods
- BRAT diet (bananas, rice, apples, toast)
These recommendations help manage symptoms and prevent complications.
What fluids are recommended for severely dehydrated patients?
- Normal saline
- Lactated Ringer’s solution
These are typically given by bolus followed by infusion until the patient is well hydrated.
What antibiotics are commonly considered for empiric therapy in diarrhea?
- Ciprofloxacin
- Levofloxacin
- Azithromycin
These cover the majority of enteric pathogens and are used especially in immunocompromised patients.
Why are empiric antibiotics discouraged for patients with bloody diarrhea?
They may increase the risk of developing hemolytic uremic syndrome in patients with Shiga toxin–producing E. coli
This is particularly concerning in pediatric patients.
What is the role of antimotility agents in diarrhea management?
They provide significant relief of symptoms in nontoxic patients with acute watery diarrhea
Loperamide is commonly used but should be avoided in severe colonic inflammation.
What are probiotics proposed for in the context of diarrhea?
Restoring normal gastrointestinal flora
They may be effective but studies show mixed results regarding their efficacy in acute infectious diarrhea.
What is the typical disposition for patients with uncomplicated, acute diarrhea?
Usually discharged following assessment and symptomatic treatment
Hospitalization may be necessary for hemodynamic instability or unclear diagnosis.
What should be arranged for patients with multiple comorbidities being discharged with diarrhea?
Close outpatient follow-up
This is important to ensure continued care and monitoring.
Fill in the blank: Oral rehydration is the treatment choice for _______ fluid losses.
mild
Factors increasing probablity of Non benign diarrhea
What does the term constipation refer to?
A symptom or complex of symptoms and not a specific diagnosis
How do health care providers typically define constipation?
Based on stool frequency
What symptoms do patients often associate with constipation?
- Straining
- Hard or infrequent stools
- Pain during bowel movement
- Feeling of incomplete evacuation
- Abdominal bloating
What is the definition of chronic constipation?
Presence of symptoms for at least 3 months
What term is used when constipation becomes severe with constant pain?
Obstipation
In which demographic is constipation more common?
- Women
- Elderly
- Those with high body mass index
- Sedentary lifestyle
- Low socioeconomic status
What age group shows a significant increase in the prevalence of constipation?
After the age of 70 years
What factors contribute to high prevalence of constipation in elders?
- Diet low in fiber
- Lack of adequate fluid intake
- Sedentary habits
- Multiple medications
- Various disease processes
What are the components of normal gastrointestinal secretions per day?
9 to 10 L/day of secretions and ingested fluids
What is primary constipation also known as?
Functional constipation
What are the three subtypes of primary constipation?
- Normal transit constipation
- Slow transit constipation
- Disorders of defecation
What characterizes normal transit constipation?
Regular bowel movements that may be hard or require excessive straining
What causes slow transit constipation?
Neurologic changes impacting the colon’s ability to contract
What is dyssynergistic defecation?
Difficulty coordinating abdominal muscle pushing with pelvic floor muscle relaxation
What is secondary constipation caused by?
- Diet
- Medications
- Certain medical or psychiatric conditions
What role does fiber play in relation to constipation?
Increases stool weight, leading to decreased colonic transit time
What symptoms may indicate acute rectal pathology?
Symptoms that have evolved quickly and are worse with defecation
Which medications are commonly implicated in causing constipation?
- Opioids
- Iron supplements
- Calcium channel blockers
- Antidepressants
What should be assessed during the abdominal examination for constipation?
Presence of tenderness, mass, distention, or abnormal bowel sounds suggesting obstruction
What may be revealed during anorectal inspection?
- Fissures
- Hemorrhoids
- Abscess
- Rectal prolapse
What is the value of plain abdominal radiography in patients with constipation?
Of significantly limited value
What should be done if blood is found in the stool?
Consider hemoglobin level or complete blood count (CBC) to check for anemia
What is the typical management approach for acute constipation without an apparent emergent cause?
Symptomatic treatment with referral for outpatient evaluation
What may outpatient testing include after empirical treatment failure?
- Blood tests for metabolic or endocrine causes
- Colonic transit studies
- Anorectal manometry
Causes of constipation
Algorithmic approach to diagnosis of constipation
What is the first step in assessing a patient with constipation?
Assess whether there is associated abdominal pain.
True or False: Constipation is commonly associated with morbidity or mortality.
False.
What are the serious conditions that can be missed if constipation is not evaluated properly?
Bowel obstruction or perforation.
What is stercoral perforation and what causes it?
It results from severe chronic constipation causing fecal impaction and pressure necrosis.
How is stercoral perforation typically diagnosed?
On CT imaging.
When should surgical consultation be considered in a patient with constipation?
For suspected perforation or obstruction.
What is the goal of treating acute constipation?
Identifying the underlying cause and providing symptom relief.
What preventative measures can be recommended for further episodes of constipation?
- Increased fluid intake
- Increased exercise
- Increased dietary fiber
- Additional sources of bulk
What should be the focus of initial treatment for acute constipation without structural abnormalities?
Addition of osmotic or stimulant laxatives.
What are the seven main classes of commonly used laxatives?
- Softeners
- Bulking agents (fiber)
- Osmotic agents
- Stimulants
- Intestinal secretagogues
- Prokinetic agents
- PAMORAs
What do intestinal secretagogues do?
Stimulate intestinal fluid secretion and increase stool fluid content.
What type of agents are effective for patients with chronic idiopathic constipation?
Prokinetic agents that target the serotonin receptor (5-HT4 receptor agonists)
These agents increase colonic propulsion without cardiac side effects.
What bowel regimen is recommended for patients with chronic opioid use to prevent constipation?
High levels of dietary fiber and daily administration of stimulant laxatives
Examples include added prunes or figs.
What are PAMORAs designed to manage?
Opioid-induced constipation
These are used for patients who have failed other therapies.
Which receptors do PAMORAs selectively block?
Gastrointestinal μ-opioid receptors
They do this without compromising the centrally mediated effects of opioid analgesia.
Name the three drugs classified as PAMORAs.
Methylnaltrexone (Relistor), naldemedine (Symproic), naloxegol (Movantik)
Methylnaltrexone can be administered both subcutaneously and orally, while the others are orally administered.
What is generally considered the safest choice for enemas?
Warm tap-water enemas
These are often used to provide relief from constipation.
What procedure may be necessary for immediate relief in some patients with severe constipation?
Manual disimpaction
This is especially true for elders with large amounts of stool in the rectal vault.
In rare cases, what may be required for disimpaction?
Analgesia or procedural sedation
This is done to ensure patient comfort during the procedure.
What is the mechanism of action for bulk laxatives?
Indigestible fiber attracts water, leading to larger, softer fecal mass.
What is the maximal recommended dosage for Psyllium (Metamucil) in males?
30 g
What type of fiber is Polycarbophil (Fibercon)?
Synthetic fiber of polymer of acrylic acid, resistant to bacterial degradation.
How do osmotic laxatives function?
Draw water into the intestines along osmotic gradient.
What is the maximal recommended dosage for Magnesium hydroxide (milk of magnesia)?
4800 mg per day
What is a common use of Sodium phosphate (Fleet PhosphoSoda)?
Before colonoscopy.
Fill in the blank: Lactulose is a __________ not absorbed by the small intestine.
synthetic disaccharide
What is the recommended dosage for Polyethylene glycol and electrolytes (GoLYTELY, MiraLax)?
34 g per day
What is the onset of action for Sorbitol?
0.25–1 hr
What do stimulant laxatives do?
Stimulate intestinal motility or secretion.
What is the maximal recommended dosage for Senna (Senokot, Ex-Lax)?
100 mg daily
What is a common effect of Docusate sodium (Colace)?
In many studies, no better than placebo.
What is the onset of action for Mineral oil?
6–8 h
What is the function of intestinal secretagogues like Lubiprostone?
Used in Chronic Idiopathic Constipation (CIC).
What is the recommended dosage for Linaclotide (Linzess) in IBS-C?
290 μg daily
What is the onset of action for Methylnaltrexone (Relistor)?
30–60 min
True or False: Naloxegol (Movantik) is used in opioid-induced constipation.
True
What is the recommended dosage for Plecanatide (Trulance)?
3 mg daily
