Lecture 5: Disorders of the SI/Colon Flashcards
SI anatomy image review
What are the 3 phases of digestion?
- Intraluminal: dietary fats, proteins, carbs are hydrolyzed and solubilized by pancreatic and biliary enzymes
- Mucosal: brush border enzymes hydrolyze peptides and saccharides
- Absorptive
What is celiac disease?
Abnormal IMMUNE response to gluten/gliadin.
Permanent disorder.
Who is at highest risk for celiac disease?
Caucasians
What happens to the SI in celiac disease?
Atrophy of the SI villa and malabsorption of nutrients.
Antibody production will occur as well.
How does classic celiac disease present?
- Diarrhea, steatorrhea, flatulence
- Dyspepsia
- Wt loss
- Abd distension
- Weakness, muscle wasting
- Growth retardation in children
- Resolution of symptoms upon not eating gluten food.
What skin findings are seen in celiac disease?
Dermatitis Herpetiformis (pruitic, papulovesicular rash)
If this is present, good chance they have celiac.
What serology test is the initial workup for celiac disease?
IgA TT antibody test
Extremely sensitive and specific.
Pt should make NO diet changes prior to this test!
What are the secondary serologic antibody tests we might order for celiac disease?
- Total IgA
- IgA anti-endomysial antibody
- IgG DGP
What is the standard way of diagnosing celiac disease with a positive serologic test?
Endoscopic mucosal biopsy of both the proximal and distal duodenum.
Should show blunting or loss of intestinal villi.
What might endoscopy show on imaging for celiac disease?
- Atrophy of duodenal folds
- Nodular, scalloping of duodenal folds, fissuring, mosaic pattern
What causes whipple disease?
- Tropheryma whipplei
- G+, non-acid fast, PAS positive bacillus
- Fecal-oral transmission
How does whipple disease typically present?
- Arthralgias (MC symptom reported first)
- Diarrhea
- Abd pain
- Wt loss (MC SYMPTOM OVERALL)
What PE findings are seen in whipple disease?
- Low-grade fever
- Evidence of malabsorption
- Enlarged joints
- LAN
What is the whipple disease mnemonic?
- Weight loss
- Hyperpigmentation of skin
- Infection with tropheryma whipplei
- PAS positive granules in macrophage
- Polyarthritis
- LAN
- Enteric involvement
- Steatorhhea
WHIPPLES
How do you diagnose whipple disease?
EGD with biopsy of duodenum showing macrophages with PAS bacilli/granules
PCR can confirm if inconclusive
How do you treat whipple disease?
- IV rocephin or meropenem
- Followed by Bactrim for 1 year
What is bacterial overgrowth?
- Colonic bacteria seen in excess in SI.
- Proximal short bowel normally has a small amt of bacteria.
What are the causes of bacterial overgrowth?
- Motility disorders
- Anatomic disorders (adhesions)
- Diabetes
- Immune disorders
What are the common symptoms of small intestinal bacterial overgrowth? (SIBO)
- Nausea
- Bloating
- Gas
- Abd pain
- Fatigue
- Cramps
- Acne rashes
- Wt loss
How do we confirm SIBO?
- Small intestine aspiration w/ cultures (highly invasive)
- Carbohydrate breath test with lactulose and carb cessation
How do you treat SIBO?
- Ciprofloxacin 500mg BID
- Augmentin
- Bactrim
7-10 days
Also, correct anatomic defect if present (like adhesions)
What causes short bowel syndrome? (SBS)
- Removal of a portion of the SI
- Crohn’s, ischemia, tumor, trauma, mesenteric infarction, or volvulus
How does a terminal ileal resection present?
Malabsorption of B12 and bile salts
How does an extensive bowel resection present?
- > 50% of SI removed
- Wt loss and diarrhea d/t malabsorption
How do you manage the initial/acute phase of SBS?
- Manage fluids/lytes
- Acid suppression with PPIs
- Parenteral nutrition
How do you manage the adaptation phase of SBS?
- Transition to oral feedings
- Complex carbs
- Low fat
- Fluids, PPIs, antidiarrheals, and ABX for SIBO
What is lactase?
Brush border enzyme that hydrolyzes lactose.
How is lactose intolerance confirmed?
Hydrogen breath test with 50g of lactose.
Must fast 8 hours prior.
What is paralytic ileus?
Neurogenic failure or loss of peristalsis in the SI without any mechanical obstruction.
Who is paralytic ileus MC in?
Hospitalized patients:
- Intra-abdominal processes such as recent GI or abd surgery
- Peritoneal irritation
- Severe medical illness
- Meds like opioids or anticholinergics
Post surgery, what is the order in which the GI system recovers?
- SI motility normalizes
- Stomach
- Colon
What occurs that causes paralytic ileus?
- Inflammatory response to intestinal manipulation and trauma
- Inhibitory neural reflexes increase sympathetic activity in the gut
- Opioids inhibit motility
How does paralytic ileus present?
- N/V/obstipation, abd discomfort
- Abd distension w/ tympany to percussion
- Diminished/absent bowel sounds
- Diffuse abd pain
How do we workup and diagnose paralytic ileus?
- Clinical dx if > 4 days
- Plain films should show distended/dilated gas-filled loops
- CT to distinguish between ileus and SBO.
What labs help r/o other causes of paralytic ileus?
- CBC: r/o infection, ischemia, abscess
- CMP: hypoK can worsen ileus
- BUN/Cr: Uremia can cause ileus
- LFTs, amylase, lipase: gallbladder/pancreatitis can cause ileus
How do we treat paralytic ileus?
- Complete bowel rest via IV fluids and NG tube
- Slowly advance diet
- Activity
- Remove any offending drugs
What preventative methods can aid with ileus?
- Avoid IV opioids
- Early ambulation
- Clear liquid diet
- GUM CHEWING (stimulates vagus nerve)
What is a small bowel obstruction? (SBO)
- Impairment of the normal flow of intraluminal contents
- Mechanical obstruction
What does a full SBO do? Partial?
- Partial is only lumen
- Full w/ strangulation will impair blood supply and cause necrosis
What secondary conditions can occur due to SBO?
- SIBO
- Distension
- Hypovolemia
- Dilation of intestines
- Feculent emesis
- Peritonitis (if no strangulation)
Everything getting clogged up
If SBO is prolonged, what could occur blood-flow wise?
- Reduced perfusion
- Tissue ischemia
- Necrosis and perforation
What is the MCC of SBO?
Post-surgical adhesions
70%
What are the S/S of SBO?
- Acute
- Nausea/vomiting
- Colicky abd pain
- Obstipation (severe/complete constipation)
- Proximal blockage: profuse emesis with undigested food
- Diffuse blockage: Diffuse and poorly localized cramps with feculent vomiting
- High-pitched tinkling sound
- Fever
What is a hallmark sign of SBO?
Dehydration, which leads to tachycardia and hypotension
When are you more likely to hear hyperactive bowel sounds in SBO?
Early on, as the GI system attempts to overcome the block.
Hypoactive comes later as it gives up.
What are the signs that suggest intestinal ischemia?
- Fever > 100F
- Tachycardia
- Peritoneal signs: guarding, rigid abdomen, rebound tenderness, disproportionate pain
How do we confirm a SBO?
Plain XRAYs of the abdomen showing dilated small bowel loops with air-fluid levels and a “ladder-like” appearance.
How do we treat SBO?
- Admit and consult surgery
- Fluid/lytes
- NG tube
- TPN
- ABX for bowel compromise
Ileus vs SBO chart
What is Ogilvie syndrome?
Acute colon pseudo-obstruction
Spontaneous massive dilatation of the cecum and proximal colon in the absence of an anatomic lesion