Constipation/Zenker diverticulum Flashcards
Constipation
general
Infrequent, irregular, or difficult evacuation of the bowels
Common reason for seeking medical attention
Acute (≤ 12 weeks) or chronic (> 12 weeks) presentation
Occurs in 15% of adults and 1/3 of elderly patients
♀>♂
constipation
etiology
Primary (Idiopathic or Functional) constipation
Not attributed to any structural abnormalities or systemic disease; 3 subtypes
Secondary constipation
Caused by systemic disease, medications, or obstructing colonic lesions
constipation
common causes
Inadequate fiber or fluid intake
Poor bowel habits
Physical inactivity
Systemic disease/disorders
Hypothyroidism, hypercalcemia, paraplegia
Medications
Opioids, diuretics, iron
Structural abnormalities
Slow colonic transit
Normal colonic transit is ~35 hours
Primary mechanisms that cause constipation:
Altered stoolconsistency
Altered bowelmotility
bold = primary cause
defecation
Mechanism
Colonic mass movements/peristalsis move intestinal contents distally into the rectum
Rectal filling activates mechanoreceptors in the rectal wall causing awareness of the need to defecate
A small amount is allowed to pass through to the anal canal by an involuntary relaxation of the internal anal sphincter (rectoanal inhibitory reflex) → determine if the rectal contents is gaseous, solid, or liquid form
Abdominal muscles contract and a Valsalva maneuver is performed while simultaneously relaxing the external anal sphincter and puborectalis muscle (pressure gradient generated between the rectum and anal canal expels the feces)
Constipation
S/Sx
Infrequent bowel movements (< 3/week)
Hard stools
Excessive straining
Sense of incomplete evacuation
Bloating
Abdominal cramping or pain
Tenesmus
Overflow diarrhea
Bristol Stool Chart
Diagnostic medical tool designed to classify the form of human feces into seven categories
constipation
diagnosis and HPI
Based on a complete history and physical examination to include a digital rectal examination (DRE)
History
Stool frequency, consistency, and color
Length of time for a bowel movement
Use of laxatives or enemas
Review prescription medications
constipation
When is additional testing recomended?
Additional testing for:
Age >50 years
Severe constipation
Alarm symptoms:
Hematochezia
Weight loss
+ FOBT (fecal occult blood test)
Inadequate response to empiric therapy
Approach to Management
with red flag features
Order colonoscopy or flexible sigmoidoscopy and biopsy to rule out colorectal cancer
Approach to Management
without red flags
Assess for secondary causes of constipation
CBC with differential, serum electrolytes, calcium, glucose, and TSH
Review medications
approach to management
for constipation with inadequate response to empiric therapy
Anorectal manometry and a balloon expulsion test
or
Colonic transit study
anorectal manometry amd a balloon expulsion test
Measure pressures inside the rectum and anus and the ability of the pelvic muscles to expel stool from the rectum
Abnormal results → defecatory disorder
colonic transit studies
Patients swallow radiopaque markers, which are then tracked through the gastrointestinal tract using x-rays
Differentiate between slow and normal transit constipation
Normal transit constipation → a disorder of the gut-brain axis
constipation Tx
Dietary and lifestyle measures
Increase dietary fiber (20-35 g/day)
Regular exercise
Increase intake of water (2L/day if not on water restriction)
Decrease constipating agents, such as dairy products, coffee, tea, and alcohol
constipation Tx
Pharm
Discontinue medications linked to constipation
Pharmacotherapy
Laxatives: fiber, osmotic, or stimulant laxative
Suppositories
Stool surfactants: Colace, mineral oil
Enemas: warm water, sodium phosphate, milk of molasses
Acute purgative/clean bowel prep: polyethylene glycol (PEG), magnesium citrate
Opioid-receptor antagonists
complications
Anal fissures
Passage of hard, lumpy stools causes a tear in the anoderm
Leads topainful defecationand rectal bleeding
complications of constipation
Hemorrhoids
Due to excessive straining with hard, lumpy stools
Leads to rectalpain, itching, and/or bleeding
complications
Fecal incontinence
Chronic constipation → formation of ahard stool mass→ progressive distention of the anal sphincter complex → patient no longer feels urge to defecate
Soft or liquid stool begins to seep around the obstructing stoolmass, causingoverflow incontinence
complications
other
Urinary retention
Syncope with straining
complications
Rectal Fecal impaction
General and Sx/Tx
Common in the elderly
↑ rectal capacity and ↓ colonic motility
Firm often puttylike mass in the rectal vault on DRE; sometimes rocklike
Symptoms: rectal pain, tenesmus, overflow (paradoxic) diarrhea: watery fecal material leaking around the impacted stool
Treatment: enema and manual disimpaction
complications
Bowel obstruction
Sx and imaging
Partial or complete
Symptoms: ↓ appetite, nausea and vomiting, abdominal pain and/or distention
Diagnosis: flat and upright abdomen x-ray or CT scan
Zenker diverticulum
general
Acquired mucosal herniation that forms in the hypopharynx
Also known as pharyngoesophageal false diverticulum
Involves the mucosa and submucosal layers; NO muscular involvement
Rare condition
Seen in patients >40 years
Zenker
Patho
Impaired relaxation of the cricopharyngeal muscle and as a result…
Pharyngeal muscles must contract more forcefully to propel food to the esophagus
↑ pressure in the hypopharynx
Herniation of the mucosa and submucosa through an area with muscle weakness creating a pouch-like structure outside the lumen of the esophagus
Zenkers
most common location
Most common location is at the Killian’s triangle (between the thyropharyngeus and cricopharyngeus muscles)
Zenker diverticulum
clin man
Retention of food particles and salivary secretions leading to:
Dysphagia – “high up dysphagia”
Regurgitation → aspiration
Sensation of food struck in the throat
Halitosis (bad breath)
Chronic cough
Weight loss
Visible lump in the neck (rare)
Zenker
Dx
Barium swallow study
Diverticulum fills with contrast media
Allows for assessment of the size, location, and character of the mucosal lining
Upper endoscopy
Zenker diverticulum
Tx
Lesions less than 2 cm rarely require treatment
Large, symptomatic diverticulum
Cricopharyngeal myotomy
Diverticulopexy
