Colorectal Disorders

Question 1

Rectal Abscess

Answer 1

• definition: bacterial infection of anal ducts and glands
  
  • → strongly associated with Crohn’s disease
• S/sxs:
  
  • severe continuous throbbing pain, fever, malaise, urinary retention
• Pe:
  
  • tender peri-anal and rectal mass
• Tx:
  
  • drain surgically
  • no abx

Question 2

Anal Fistula

Answer 2

• Strong association with Crohn’s disease → chronic inflammation of anorectal gland → tract develops connecting rectum to skin
• Tx:
  
  • surgical repair

Question 3

Anal Fissure

Answer 3

• Definition:
  
  • mucosal tear in anus associated with constipation and/or frequent diarrhea
• S/sxs:
  
  • pain with defecation
    
    • “tearing pain”
    • minimal Bright Red Blood Per Rectum
• tx:
  
  • acute:
    
    • stool softeners
    • topical anesthetics
    • sitz baths
    • increased dietary fiber
  • chronic:
    
    • botox
    • nifedipine, or nitroglycerin 3x/day
    • surgical: anal dilation and lateral internal sphincterotomy

Question 4

Bristol Stool Chart

Answer 4

Question 5

Constipation: Definition, Causes, Risks, S/sxs, PE

Answer 5

• Definition:
  
  • persistent infrequent bowel movements < 3 bm/week
  • or feeling of incomplete voiding
  • chronic = > 3 months
• Causes:
  
  • Most common cause = dietary
  • lifestyle, obstruction, muscular (pelvic floor injuries), neurogenic (MS, parkinsons), hormonal (hypothyroid, DM, pregnancy, hyperparathyroid)
• Risks: Age > 60 yo, meds (opioids), female
• S/sxs:
  
  • straining,
  • hard/pebble stools
  • feeling of retained stool
  • bloating
  • abd distention
• Pe:
  
  • hemorrhoids
  • fissures
  • fecal impaction → chronic constipation → accumulation of stuck stool
  • rectal prolapse

Question 6

Constipation: Dx & Tx

Answer 6

• Dx:
  
  • clinical
  • History is key! (timing of new drugs and symptoms)
  • Labs: CMP & TSH
  • Diagnostic Studies: RARELY USED → anorectal manometry
    
    • abdominal Xray
  • Alarm features:
    
    • melena/hematochezia
    • weight loss >10 lbs
    • fam hx of IBD or colon cancer, anemia, +FOBT
• Tx:
  
  • If alarm symptoms: tx the underlying issues→ get colonoscopy if unsure
  • 1st line: increased water/dietary fiber (psyllium, methylcellulose or prunes)
  • 2nd line: surfactants (softeners) (docusate
  • 3rd line: osmotic agents that make the body secrete more water (polyethylene glycol [miralax]/ lactulose/sorbitol/glycerine PR, Mg)
  • 4th line: stimulant laxatives (bisacodyl, senna) → CAUTION, body becomes dependent quickly
• Special:
  
  • • idiopathic constipation and IBS → lubiprostone, linaclotide
  • -opioid induced: naloxegol

Question 7

Acute vs Persistent vs chronic Diarrhea

Answer 7

• Definition:
  
  • loose or watery stools > 3x/24 hours
• Acute: ≤ 14 days → usually infectious
• Persistent: 15-30 days → often parasitic
• Chronic; > 30 days → chronic disease: IBS, IBD, celiac, etc
• Acute can turn to chronic! So don’t let the short duration fool you!

Question 8

Inflammatory/Invasive Diarrhea (Overview)

Answer 8

• Source: usually caused by invasive or toxin producing bacteria that damage the large intestinal mucosa
• S/sxs:
  
  • Smaller volume diarrhea with blood, mucus +/- leukocytes
  • Tenesmus: “Dry heaving from your butt”
  • abd pain, fever
• Tx:
  
  • supportive care and disease specific
  • DO NOT GIVE antimotility agents as the toxins will remain present longer and worsen the disease

Question 9

Non-inflammatory/ Non-invasive Diarrhea (Overview)

Answer 9

• Source: enterotoxins increase GI secretion of electrolytes → causes secretory diarrhea
  
  • → no cell destruction or mucosal invasion
• S/sxs:
  
  • large volume of diarrhea
  • vomiting
  • no fever or blood in stool
• Tx:
  
  • supportive care and disease specific tx PRN

Question 10

Campylobacter jejuni

Answer 10

• invasive/inflammatory diarrhea
• **Most common bacterial cause of diarrhea in the US**
• Most common antecedent of Guillain Barre Syndrome
• Consumption of undercooked poultry = MCC; Raw milk consumption & Puppies!
• S/sxs:
  
  • bloody diarrhea, fever, abd pain
  • guillain barre syndrome: ascending paralysis, loss of DTRs
• Dx:
  
  • stool cx with S or comma shaped gram neg rods
  • PCR = most practical and most commonly done (but not the answer on BOARDS)
• Tx:
  
  • usually self limiting
  • abx can shorten duration → Macrolides (Azithromycin)

Question 11

Yersinia Enterocolitica

Answer 11

• invasive/inflammatory diarrhea
• Sources:
  
  • contaminated pork products = most common, milk, water, tofu
• S/sxs:
  
  • of inflammatory diarrhea
  • mesenteric lymphadenitis → abd tenderness & guarding known as pseudoappendicitis
  • smaller volume diarrhea blood, mucus +/- leukocytes
  • Tenesmus: “Dry heaving from your butt”
  • abd pain
  • fever
• Dx:
  
  • stool culture = preferred
    
    • “safety pin appearance” of gram neg bacilli
• Tx:
  
  • fluids/electrolytes
  • severe diarrhea → fluoroquinolones or TMP/SMX (Bactrim)

Question 12

Enterohemorrhagic E. Coli

Answer 12

• invasive/inflammatory diarrhea)
• Produces Shiga toxin → damages the endothelial lining and leads to hemorrhage
• Most common in elderly & children
• Sources:
  
  • undercooked ground beef, unpasteurized milk or cider, day care centers
• s/sxs:
  
  • Smaller volume diarrhea with blood, mucus +/- leukocytes
  • Tenesmus: “Dry heaving from your butt”
  • abd pain, fever
  • Watery diarrhea that later becomes bloody + vomiting
• Dx:
  
  • stool cx
  • PCR
• Tx:
  
  • fluid/electrolytes
  • **avoid abx in children due to risk of hemolytic uremic syndrome**

Question 13

Salmonella Typhimurium (non-typhoid)

Answer 13

• invasive/inflammatory diarrhea
• Sources:
  
  • undercooked or raw poultry, eggs, milk, fresh product
  • contact with reptiles (Turtles)
• S/sxs:
  
  • Short incubation: 1-3 days
  • sxs of inflammatory diarrhea + vomiting
  • Smaller volume diarrhea with blood, mucus +/- leukocytes
  • Tenesmus, abd pain, fever
• Dx:
  
  • stool cx
• Tx:
  
  • Fluid/electrolytes
  • severe diarrhea → Fluoroquinolones

Question 14

Salmonella Typhi (Typhoid/Enteric Fever)

Answer 14

• invasive/inflammatory diarrhea
• Most common cause = traveling to or living in an underdeveloped nation
• Source:
  
  • fecal-oral
  • humans are only reservoir for typhoid
• S/sxs:
  
  • Classic (but rare): fever with relative bradycardia
  • “Pea soup diarrhea”
  • Rose spots (faint pink/salmon colored macular rash)
• Dx:
  
  • blood cx & Stool cx
• Tx:
  
  • fluid/electrolytes
  • Severe diarrhea → fluoroquinolonesx2 weeks (2x as long as other diarrhea tx

Question 15

Shigellosis

Answer 15

• invasive/inflammatory diarrhea
• Produces shiga toxin which is neurotoxic, cytotoxic, enterotoxic
• Sources:
  
  • fecal-oral, raw veggies
• s/sxs:
  
  • abrupt onset of explosive, watery diarrhea that becomes progressively bloody
  • tenesmus, abd pain, +/- fever, chills, anorexia, malaise, HA
• Dx:
  
  • Stool cx → positive fecal WBC/RBC
  • CBC with WBC > 50,000 (super high white count
  • Sigmoidoscopy: punctate areas of ulceration
• Tx:
  
  • fluids/electrolytes
  • severe diarrhea → fluoroquinolones

Question 16

Amebiasis

Answer 16

• (invasive/inflammatory diarrhea)
• Entameba histolica → protoza rarely seen in the US, but seen in travelers from endemic areas
• Source:
  
  • ingestion of cysts from food/water contaminated with feces
• S/sxs;
  
  • asymptomatic but may develop liver abscess
• Dx:
  
  • O&P shows cysts and RBCs
    
    • → cysts are not consistently shed so must obtain samples on 3 different days
  • ELISA (rapid & highly sensitive)
• Tx:
  
  • Metronidazole or tinidazole

Question 17

cryptosporidium

Answer 17

• General info: associated with immunocompromised pts
  
  • -fungus
  • transmission: fecal-oral
  • Most common cause of chronic diarrhea in AIDS patients
• Dx: stool O & P
• Tx: ketoconazole, control the AIDs

Question 18

Norovirus

Answer 18

• Non-inflammatory/non-invasive diarrhea
• Most common cause of gastroenteritis in adults
• Source:
  
  • fecal-oral route, contaminated food.water, fomite → associated with cruise ships, hospitals, and restaurants
• S/sxs:
  
  • Vomiting + diarrhea
• Dx: PCR
• Tx: fluids/electrolytes

Question 19

Rotavirus

Answer 19

• Non-inflammatory/non-invasive diarrhea
• Most common cause of diarrhea in unvaccinated infants and young children
• source:
  
  • fecal-oral route, contaminated food/water, fomite → associated with outbreaks in childcare centers
• S/sxs:
  
  • child presenting with fever, vomiting and non-bloody diarrhea
  • **Associated with severe dehydration in babies**
• Dx: PCR
• Tx:
  
  • fluids/electrolytes
  • Prevention: Rotavirus vaccine

Question 20

Enterotoxigenic E. Coli

Answer 20

• Non-inflammatory/non-invasive diarrhea
• Most common cause of traveler’s diarrhea
• Source:
  
  • drinking water/ice, washed unpeeled fruit
• S/sxs:
  
  • abrupt onset of symptoms of non-inflammatory diarrhea
• Dx:
  
  • Stool cx, gram stain
• Tx:
  
  • usually self limited but can prescribe cipro +/- loperamide or bismuth

Question 21

Vibrio Cholerae

Answer 21

• Non-inflammatory/non-invasive diarrhea
• Exotoxin → hypersecretion of water/ions → severe dehydration→ shock and death
• Risk factors:
  
  • overcrowding in areas of poor sanitation
    
    • occurs in outbreaks usually in developing countries
• Source: contaminated food or water
• S/sxs:
  
  • voluminous watery diarrhea
  • rice water stools, mucus flecks, no WBCs No fecal odor, blood, or pus
  • SECRETORY DIARRHEA : inhibition of water, sodium and chloride absorption
  • progressing to SHOCK/dehydration within hours, NO FEVER
• PE:
  
  • rice water-like stools
• Dx:
  
  • stool cultures show gram negative, comma shaped rods
• Tx:
  
  • Oral rehydration solution
  • Doxycycline or cipro for mod-severe cases

Question 22

Listeria

Answer 22

• Non-inflammatory/non-invasive diarrhea
• aka. the 24 hour stomach bug
• source:
  
  • processed/deli meats, hotdogs, soft cheese, pates
• s/sxs:
  
  • acute, watery diarrhea
• tx:
  
  • oral rehydration, self-limited
  • Except in pregnancy → STAT Ampicillin (preggos told not eat those foods to avoid the risk)

Question 23

Giardia

Answer 23

• Non-inflammatory/non-invasive diarrhea
• MOST common intestinal protozoan parasite in the US
• Source:
  
  • streams and wells, constamined still water
  • → associated with beavers
• S/sxs:
  
  • frothy/greasy/foul smelling diarrhea (Steatorrhea)
  • weight loss and low-grade fever is common
  • trophozoite attachment can cause inflammation and villus damage in small intestine and extremely large numbers may lead to a direct physical blockage of nutrient uptake such as Vitamin B12
• Dx:
  
  • O & P cx: trophozoites/cysts in stool
• Tx:
  
  • Oral rehydration + metronidazole, tinidazole,oralbendazole

Question 24

Clostridium Difficile

Answer 24

• Risk Factors: Antibiotics suppress normal flora → especially Clindamycin in adults, amoxicillin in children
• complications:
  
  • toxic megacolon
• S/sxs:
  
  • Mild disease:
    
    • Water diarrhea > 3x/24 hours (Cardinal symptom)
    • cramping, abd pain
    • +/- fever, bloody or mucoid stools, anorexia
  • Severe disease: (plus the above)
    
    • diffuse abd pain & distention
    • hypovolemia
    • lactic acidosis
    • marked leukocytosis
• Dx:
  
  • stool testing (PCR, nucleic acid amplification test)
• Tx:
  
  • CONTACT PRECAUTIONS
    
    • oral vanco (IV is not effective)
    • Fidaxomicin = also expensive but $$$$
    • Metronidazole = 1st line in children

Question 25

Diverticulosis

Answer 25

• Definition:
  
  • having diverticula outpouchings due to herniation of the mucosa into the wall of the colon along natural openings at the vasa recta of the colon, Most common in the Sigmoid (left) colon
• Risks:
  
  • low fiber diet, constipation, obesity
• Prevention:
  
  • healthy diet (avoid nitrites)
• S/sxs:
  
  • *usually asymptomatic incidental finding*
  • painless hematochezia
• Dx:
  
  • colonoscopy = diagnostic & therapeutic
• tx:
  
  • Asymptomatic:
    
    • high fiber diet, seeds & nuts are okay
  • Bleeding:
    
    • bleeding usually stops spontaneously
    • can resuscitate with IV fluids and blood if needed
    • endoscopic therapy to control bleeding
    • Surgery: resection of bleeding colon segment, right hemicolectomy (if unable to identify source of bleed)

Question 26

Diverticulitis

Answer 26

• Definition: inflammation or infection of a diverticulum. Microscopic perforation of a diverticulum leads to inflammation & focal necrosis.
• Most common in the Sigmoid (left) colon → LLQ pain
• complications:
  
  • bowel perf, fistula formation: bladder, vagina
  • abscess, bowel obstruction
• S/sxs:
  
  • LLQ pain
  • low-grade fever
  • abd distention
  • N/V
  • change in bowel habits: constipation/diarrhea
  • flatulence, bloating
• PE:
  
  • usually normal → may have tender, palpable mass
  • Fistula→ colovesicular (air bubbles in urine, fecaluria
    
    • colovaginal (air or stool via vagina, abd pain, fever)
• Dx:
  
  • CT scan = imaging of choice
    
    • bowel wall thickening
    • *barium enema & endoscopy contraindicated during initial stages because of risk of perforation
  • Labs: leukocytosis, elevated CRP
• Tx:
  
  • Uncomplicated:
    
    • tx outpatient with oral abx (metronidazole & Cipro) x 7-10 days
    • clear liquid diet
  • Complicated:
    
    • fistula/abscess: surgery & abx

Question 27

Hemorrhoid Degrees

Answer 27

• 1st degree: small hemorrhoids protruding into canal
• 2nd degree: prolapse but reduce spontaneously
• 3rd degree: must be manually reduced
• 4th degree: irreducible

Question 28

Hemorrhoids

Answer 28

• Definition:
  
  • internal/external hemorrhoids are separated by anatomically by the dentate line
• Causes:
  
  • increased pressure → dilated submucosal veins due to constipation, straining, sitting too long, bicycling
• S/sxs:
  
  • internal hemorrhoids:
    
    • bring red blood, rectal prolapse, PAINLESS
  • external hemorrhoids;
    
    • BELOW the dentate line → PAINFUL
    • asx until they are thrombosed → BRBPR (minimal bright red blood per rectum), swelling, burning, pruritus, and wetness in anal area/ sudden extreme PAIN lasting for several days, may ulcerate and bleed
  • Dx:
    
    • clinical for both
  • Tx:
    
    • internal:
      
      • high fiber diet, stool softener, topical steroids (hydrocortisone)
      • band-ligation
      • surgical excision for prolapse
    • external:
      
      • hydrocortisone cream
      • sitz bath
      • stool softener
      • witch hazel
      • thrombosed that does not subside within 48 hours must be excised under local anesthesia

Question 29

Crohn’s Disease

Answer 29

• INFLAMMATORY BOWEL DISEASE
• Where: can occur anywhere in GI tract, from mouth to anus (RECTAL SPARING) most common = terminal ileum!!
• Who:
  
  • Females > males, ashkenazi Jews (Eastern European Jewish Ancestry)
• Bimodal Peaks: 15-30, 60-70
• S/sxs:
  
  • abd pain (Esp RLQ due to terminal ileum being most common)
  • diarrhea (usually not bloody)
  • weight loss (lots of weight loss)
  • vitamin deficiency
  • aphthous ulcers
• Complications:
  
  • fistulas, abscess, bowel perf, granulomas
• Dx:
  
  • Colonoscopy/Endoscopy → Transmural lesions, skip lesions, cobblestoning. (DIAGNOSTIC)
  • Labs Cannot diagnose but can point in right direction:
    
    • +ASCA
    • ESR/CRP (vague identification)
• Tx:
  
  • Mesalamine (nsaid) for mild disease
  • steroids for acute flairs only
  • then 6MP/AZA, then anti-TNF = immunomodulators → tend to be most successful txs
  • Surgery is NOT curative in crohn’s (only used when meds fail)

Question 30

Ulcerative Colitis

Answer 30

• INFLAMMATORY BOWEL DISEASE
• ONLY OCCURS IN THE COLON : Begins in rectum and then spreads through the colon
• M = F, most common = caucasian, but increasingly fast in asian/hispanic populations
• S/sxs:
  
  • abd pain (most commonly in LLQ)
  • tenesmus
  • bloody diarrhea → due to ulcerations
  • -mucoid stools
  • prei-anal tags
• Complications:
  
  • toxic megacolon
  • primary sclerosing cholangitis, colon cancer: need to get an annual colonoscopy starting 10 years after initial diagnosis
• Dx:
  
  • Sigmoidoscopy → uniform inflammation starting in the rectum, submucosal ulcerations, pseudopolyps
  • Colonoscopy & barium enema CT in acute disease
  • Labs:
    
    • P-ANCA +
    • ESR/CRP
  • Barium Studies → loss of haustral markings (lead pipe sign)
• Tx:
  
  • smoking helps in ulcerative colitis → decreases immune response
  • Sulfasalazine works in colon only
  • steroids for acute flairs only
  • 6MP/AZA if sulfalasize does not work
  • Anti-TNF = immunomodulators → tend to be most successful treatments

Surgery = curative in UC (only used when other tx fail)

Question 31

Irritable Bowel Syndrome: Info, S/sxs, PE

Answer 31

• Definition;
  
  • chronic, functional, idiopathic pain disorder with no organic cause, not an inflammatory process
• Epidemiology:
  
  • onset most common in late teens, early twenties Most commonly diagnosed GI illness (10-15% of population
• Risks:
  
  • gastric bypass surgery
• S/sxs:
  
  • abd pain: postprandial (occuring after a meal)
  • altered bowel habits: diarrhea, constipation, or alteration between both
  • abd distention (Gas pockets)
• Alarm sxs:
  
  • Gi bleed
  • anorexia/weight loss
  • fever
  • family hx of GI cancer, IBD
  • persistent diarrhea → dehydration
  • severe constipation/impaction
• PE:
  
  • *Normal
  • stable weight (vs IBD which has weight loss)

Question 32

Irritable Bowel Syndrome: Diagnosis & Tx

Answer 32

• Dx:
  
  • Diagnosis of exclusion (after work-up with colonoscopy, abd CT)
  • Rome IV Criteria:
    
    • *Recurrent abd pain at least 1day/week for at least 3 months with ⅔ criteria:
      
      • related to defecation
      • onset associated with change in stool frequency
      • onset associated with change in stool form
  • Tx:
    
    • lifestyle & dietary changes (low FODMAP) are first line (low fat, high fiber, unprocessed foods)
    • avoid drinks with sorbitol, or fructose
    • sleep, exercise, smoking cessation

Constipation symptoms:

• prokinetics: fiber, psyllium polyethylene glycol
• No response: lubiprostone, linaclotide

Diarrhea symptoms:

• loperamide, eluxadoline, rifaximin, bile acid sequestrants (cholestyramine)
• Anticholinergics, antispasmodics (Dicyclomine)

Question 33

Fecal Impaction

Answer 33

• Definition:
  
  • large lump of dry hard stool that remains stuck in the rectum
  • Most common cause = chronic constipation
• Risk factors:
  
  • bed-ridden patients
  • medications: anticholinergics, narcotics, laxatives (overused then suddenly d/c’ed)
• S/sxs:
  
  • abd distention/cramping
  • rectal bleeding
  • small, semi-formed stools
  • suddenly watery diarrhea (only liquid stool is able to pass around fecal obstruction)
• Dx: rectal exam will reveal a hard mass of stool in rectum
• Tx:
  
  • disimpaction

Question 34

Toxic Megacolon

Answer 34

• Definition: non obstructive, extreme colon dilation > 6cm & signs of systemic toxicity
• Etiology:
  
  • complications of IBD, C. diff , infectious colitis, ischemic colitis, volvulus, diverticulitis, radiation, & obstructive colorectal CA
• S/sxs:
  
  • PROFOUND bloody diarrhea
  • abd pain, very tender
  • abd distention
  • N/V
  • toxic appearing
  • fever
• PE:
  
  • abd tenderness & distention
  • systemic toxicity: AMS, fever, tachycardia, hypotension, dehydration
• Dx:
  
  • abd xray: colon dilation > 6cm
  • fever, tachycardia, leukocytosis, anemia (3)
  • hypotension, dehydration, electrolyte abnormalities, AMS (1)
• Tx:
  
  • EARLY surgical consult
  • Supportive: complete bowel rest, bowel decompression with NG tube, broad-spectrum abx, fluid replacement
  • C.Diff? Stop the offending agent, give vanco & metronidazole