81. Large intestine Flashcards
IBS: what is this?
abdo pain, bloat, altered bowel habits - unclear pathophys but includes intestinal permeability, immune function, alt gut microbiome, motility and psychosocial status
IBS: Rome IV criteria dx
recurrent abod pain >1 day/week in previous 3mo, onset >6mo pre dx:
Abdo pain + at least 2:
pain in defection
change in freq stool
change in form
NONE of:
age >50
recent change in bowel habits
overt GIB sx
nocturnal pain or passage of stool
unintentional w loss
family hx CRC or IBD
palpable abdo mass or lymphadenopathy
evidence IDA
+ FOBt
Red flags of GI sx: list 8
age >50
recent change in bowel habits
overt GIB sx
nocturnal pain or passage of stool
unintentional w loss
family hx CRC or IBD
palpable abdo mass or lymphadenopathy
evidence IDA
+ FOBt
DDX IBS: 3 main categories
IBS with constipation vs diarrhea with mixed
IBS with constipation ddx - 5
Bowel obstruction
Malignancy
Adult-onset Hirschsprung disease
Rectocele
Paradoxical closure of the anus during defecation
IBS with diarrhea ddx - 5
Bacterial or parasitic intestinal infection Inflammatory bowel disease
Lactose intolerance
Malabsorption
Radiation proctocolitis
Celiac disease
IBS With Mixed Symptoms - ddx 6
Inflammatory bowel disease Ureteral colic
Bowel obstruction
Diverticular disease Gastroesophageal reflux of ulcer Liver or pancreatic disease
Lead toxicity Porphyria
management of IBS
low fodmap diet (fermentable, oligosacc, disacc, monosac and polyols diet (wheat, rye, garlic, onions, lactose containing, figs, honey, blackberries, lychee)
ondans
cbt
RF of diverticular disease
smoking
nsaid
PinA
Obese
red meat
high refined carb diet
Diverticular disease pathophys
diverticulosis: asx multiple divertiula (herniation of inner mucosa and submucosa layers of intestinal wall through muscular layers - often sigmoid colon
What 4 main factors contribute to development of colonic diverticula (4 categories)
weakness bowel wall
high intraluminal pressure
other assoc factors - seasonal, smoke, age
obesity
Diverticulititis: what is this?
inflamm of diverticula (typ sigmoid so LLQ)
low grade fever
nausea/emesis
altered bowel habits in 24h
abdo distensin possible
DDX of diverticulitis
colitis (either inflammatory or ischemic), ureteral stones, inguinal hernia, or pelvic or ovarian pathology, including an ectopic pregnancy or pelvic inflammatory disease. Appendicitis should be considered when symptoms are predominantly right-sided.
Diagnostic testing for diverticulitis and ddx
cbc
urinalysis if worry colovesical fistula
abdo ct with contrast for “itis” disease
Findings of diverticulitis on CT scan:
colonic wall thickening
pericolonic fat stranding
localized perf
abscess
free air or fluid
Management of Diverticulosis in general
high fiber diet
PA
Uncomplicated diverticulitis tx
hospitalization for IV abx and bowel rest if immuncom, elderly, mult moboridities, poor social support, unable to tolerate PO
oral therapy for outpt:
* Ciprofloxacin, 500 mg PO bid and metronidazole, 500 mg PO q8h or
* Amoxicillin-clavulanate, 875 mg–125 mg PO BID
Complicated diverticulitis tx:
bowel rest
IV abx:
Mild to Moderate Infection
* Pediatric:
*Metronidazole7.5mg/kgIVq6hANDceftriaxone50mg/kgIVoncedaily
OR
* Gentamicin 2.5 mg/kg IV q8h AND metronidazole 7.5 mg/kg IV q6h
* Adult:
* Metronidazole 500 mg IV q8h plus
* Ceftriaxone 1 g IV q24h or
* Ciprofloxacin, 400 mg IV q12h or * Levofloxacin 750 mg IV q24h or
* Ampicillin-sulbactam, 3g IV q6h
Severe/Complicated Infection
* Piperacillin/tazobactam 3.375 g IV q6h or 4.5 g (100 mg/kg) IV q8h OR
* Metronidazole 500 mg IV q8h (7.5 mg/kg IV q6h) PLUS Cefepime 2 g (50 mg/
kg) IV q12h OR
* Ertapenem,1gIVq24h(weight-baseddoseinpediatrics:15mg/kg/dose
IV BID)or imipenem/cilastatin, 500 mg IV q6h (weight-based dose in pedi- atrics: 60 to 100 mg/kg/day divided q6h) or meropenem, 1 g IV q8h (weight-based dose in pediatrics: 20 mg/kg/dose IV q8h)
concern for perf, sepsis, decline despite conservative - see surgery for consideration perc drain (esp if larger abscess >5cm)
Causes of LBO
CRC malignancy
IBD
ischemia
adhesions
endometriosis
radiation
extrinsic: impingement intestinal lumen - ovarian ca, hernia
MC location for LBO?
sigmoid due to smaller lumen of sig and desc colon
-imp distinction distal or proximal to splenic flexure (tumor mc distal to this)
What is Ogilvie’s syndome?
may mimic LBO
acute colonic distension w/o evidence mech obstruction
functional due to incr symp tone or decr parasymp
top 4 causes of LBO
CRC ca
volvulus
diverticulits
compression from other malignancy or met disease
Initial imaging for LBO?
supine and upright plain film for assessment distended colon >6cm diameter, but small bowel may be >3cm
-to look for perf in particular
then ct for location and cause
Management of LBO and Ogilvie’s in the ED
IVF
lyte replacement
IV pain control, antiemetic
NPO
NG tube
conservative unsuccessful 3d - consider neostigmine 2mg IV or colonic decomp:
if volvulus or fails conservative - surg/endoscopic decompression
How does neostigmine work for LBO?
incr ach for colonic motility but risk of ?toxic megacolon?
Volvulus age group in elderly?
60-70
What is volvulus?
loop of bowel twisting around itself and mesentery –> obstruction, also maybe ischemia if tight enough
Where does most volvulus occur?
sigmoid, cecum > transverse colon > splenic flexure
Complications of volvulus
ischemia
gangrene
perf
death
Who is at risk for volvulus at sigmoid?
residents LT care
neurologic/psych disease due to alt in colonic motility
chr constipation also possible issue
How much twisting can mesentery of sigmoid handle?
180
Cecal voluvlus - mc causes fo this?
RF?
congenital incomplet fusion of cecal mesentary in posterior abdo wall
RF: chr constip, high fiber diet, laxative use, hx lap, pregnancy, pelvic surg, colonoscopy, Long distance running
Sigmoid volvulus appearance on xr?
coffee bean sign - bowel bent inner tube appearnace
Differentiation cecal volvulus vs sigmoid: example of tool to help
contrast enema
“whirl sign” on ct
Management of sigmoid volvulus
IVF
Lytes, coagulopathy addressed
abx if gangene or perf
endo decompression - or if gangrene, doesn’t work, surg
Cecal volvulus management?
IVF
coagulopathy addressed, lytes addressed
surgery - cannot do endoscopy here
What is intussusception?
lead point changes motility allowing proximal aspect of intestine to telescope into another
What age. in childre in intusseception common? vs adults?
4-10y
rarer - concern for neoplasm/malignancy (mean age 50)
Sx of intussusception in kids and diagnostic tool of choice
acute onset, intermittent abdo pain, crying, pulling up knees and emesis
u/s
Sx of intussusception in adults and diagnostic tool of choice
acute onset abdo pain, vomit, rectal bleed
ct
Management intuss kids vs adult
kid - reduction - hydrostatic or pneumatic
adult: surg
Where does most intuss occur in kids?
ileum through ileoceccal valve into cecum
idiopathic cause or related to Peyer’s patch in infection
Peds intuss management:
In pediatric intussusception, the treatment of choice for the stable child is a trial of pneumatic reduction with x-ray guidance, or hydro- static reduction with ultrasound guidance when appropriate radiologic facilities are available.12 The choice of hydrostatic or pneumatic reduc- tion is largely dependent on institutional preference. Both have higher reduction rates when compared to barium. The reduction procedure is typically performed by a radiologist and may prevent the need for surgery. Reduction of pediatric intussusception is sufficient treatment in 80% of patient
When might need to do surgery in ped intuss?
ischemic bowel necrosis
pathologic lead point
IBD Crohn’s vs UC: inflamm type and location
C: transmural inflam, skip lesion in GI tract
UC: Superifical, cont colon or rectum
IBD Crohn’s vs UC: mc extraintestinal sx
C: athritis, apthous stomatitis, uveitis, erythema nodosum, ank spond
UC: inflamm athropathies, PSC, skin/eye/bone issues possible
IBD Crohn’s vs UC: dx
endoscopy, elevated fecal calprotectin, stool lacterferrin
crohn: ASCA vs UC: p-anca
IBD Crohn’s vs UC: tx
C: uleal release budesonide, systemic steroids, immunomod, biologics, mult surg
UC: rectal/oral aminosalicyyclate, steroids, immunomod, biologics, surg (colectomy) can be curative
General pathophys of IBD
dysreg of host immune system so no longer tolerates normal gut flora/bacteria
Typical presenting sx of IBD
abdo pain/tenesmus
bloody diarrhea
w loss
IBD children sx
diarrhea, growth or pubertal delay, weight loss, rectal bleeding, anemia, pallor, fatigue, perianal skin tags, fistulae or abscesses, erythema nodusum or pyoderma gangrenosum, seronegative rheumatic joint pain, or family history of IB
Toxic megacolon: what is this?
pathologic dilation of colon from inflamm of sm layers in intestine –> m paralysis, dilation, perfoation if untx
RF meds for toxic megacolon
anticholinergics
antimotility agents
narcotics
antidep
Extraintestinal manifestations of IBD: skin
erythema nodosum
pyoderma gangrenosum
Extraintestinal manifestations of IBD: eyes
episcleritis
scleritis
uveitis
Extraintestinal manifestations of IBD: joints
arhtritis
sacroilitis
Extraintestinal manifestations of IBD: bone
osteoporosis
Extraintestinal manifestations of IBD: spine
ank spond
Extraintestinal manifestations of IBD: liver
primary sclerosing cholangitis
Extraintestinal manifestations of IBD: heme
dvt/pe
Confirmatory testing for IBD
endoscopy with bx
UC mild disease defn
- Fewer than four stools/day
- Stools may contain some blood
- No systemic signs of toxicity (e.g., fever, tachycardia, anemia, elevated
erythrocyte sedimentation rate)
UC mod disease defn
- More than four stools/day
- Minimal signs of toxicity
UC sev disease defn
- More than six bloody stools/day
- Signs of systemic toxicity
Crohn disease: mild to mod disease sx
- Patient ambulatory and able to eat
- Nodehydration
- Notoxicity
- No significant abdominal pain or mass
- Weight loss of 10%
Crohn disease: mod to seve disease sx
- Mild disease that has failed to respond to treatment
- Patient may have some systemic toxicity, significant weight loss, anemia
- Fever, some abdominal pain or tenderness, intermittent nausea or vomiting
Crohn disease: sev disease sx
- Persistence of symptoms during corticosteroid or biologic (e.g., infliximab) therapy
- High fever, persistent vomiting
- Intestinalobstruction
- Reboundtenderness
- Cachexia
- Abscess
Crohn’s: tx mild mod disease:
In general, mild disease can be treated by budesonide or oral steroids, whereas more severe disease often requires systemic IV corticosteroids, immunomodulators, or an anti- tumor necrosis factor (TNF) biologic strategy.
-bud 9mg PO daily x8 weeks (ileal release in particular)
-mild-mod GI: PPI
-extensive includes anti TNF, systemic corticosteroids induction 0.5-0.75mg/kg/day PO pred - higher if severe 40-60
Crohn’s: tx mod to severe disease:
systemic steroids, early introduction to an immunomodulator, such as thiopurines or methotrexate, can be considered to reduce the risk of flare when steroids are withdrawn. Immunomodulators have a relatively slow onset, so are used adjunctively, and have limited use as monotherapy. Azathioprine 1.5 to 2.5 mg/kg/day PO or mercaptopurine 0.75 to 1.5 mg/kg/day PO may be used as an adjunctive therapy or steroid sparing agent. Methotrexate 25 mg/week subcutaneously or intramuscularly is the standard induction dose, with measurement of CBC and liver function tests prior to the initiation of therapy.
Severe/fluminant Crohn disease amangeemnt
aggressive therapy, gastroenterology consultation, and often hospitalization. For patients with symptoms suggestive of obstruction, mass, or abscess, surgical consultation is prudent. Evaluation includes CBC, complete metabolic panel, blood cultures, stool culture, C difficile toxin antigen, urinalysis, and abdominal CT or MRI.
When surgery in Crohn disease?
-fail medical therapy
-serious complications including abscess (perc drain if 5cm or greater)
-strictureplasy if resection <10cm
UC: mild-mod tx
5-asa including mesalazine and sulfasalazine
proctitis PR of above
not responding to above: budesonide
if fail: sys predn: 0.5-1mg/kg PO pregn
UC: mod severe dis tx
Cyclosporine, but given complications including (myelosupp, electrolyte disturbances, hepatic tox, nephro toxic, risk PCP) more likely inflximab
avoid antichol, antidiarrheas, or procedures like colonsocpy barium enema as may risk toxic megacolon
surg if refractory to above
Pregnancy and IBD: how to manage?
-avoid cipro and metronidazole first trimester
-steriods incr risk DB
-5-ASA, immunomod and anti TNF safe in pregnancy
Toxic megacolon tx:
IVF
IV corticosteroids
abx
tx lyte abn
assess for intestinal infection
Colonic ischemia: how does this occur?
nonoccusive: hypoperfusion and reperfusion injury - see bowel wall edema nad subepithelium hemorrhage so mucosa ulcerates
Colonic ischemia: primary insults?
-Cardiac: arrh, HF, shock
- vascular: AS, embolic, thrombotic, vasculitis
-infection: ecolo 0157:h7, hep b, cmv
-iatrogenic: surg on aorta
-physiologic : LD running
-coke/meth
Colonic ischemia: weird RF?
copd
Colonic ischemia: RRF diseases
copd, ibd, collagen vascular disease, heme disorders, ld running
meds: anti htn, vascon, antipsychotic, OCP, antidiarrheal, pseudophed, immunosuppressive agent
Colonic ischemia: why is colon so at risk?
lowest flow state of all splancnhic organs, limited collaterals
usually L sided correlating with IMA
Colonic ischemia: features of presentation
mild crampy abdo pain
n/v
may have rectal bleed
Colonic ischemia: lab tests?
none sp but check wbc, lactate, decr hb, bicarb, incr LDH
Colonic ischemia: ct features consistent?
mes fat stranding
abn colon wall enh
thumbprinting
wall thickening
luminal narrowing
inner wall hypoperfusion
sev: pneumatosis linearis, bowel dilation, pericolonic free fluid
Colonic ischemia: best diagnostic testing?
colonoscopy for bx
Colonic ischemia: absence of surgical complications, tx?
bowel rest
hydration
pain management
sign fx - abx
Sterocoral colitis: what is this?
rare complication of chronic constipation and fectal impaction leading to inc intraluminal pressure wall necrosis, ischemic olitis, stercoral ulcer formation and concern for perf
Stercoral colitis: common where (ie which part of colon)?
anterior rectum
rectosigmoid junction
apex of sigmoid colon
Stercoral colitis: dx?
ct - fecal impaction with hard calcified fecal mass, colon dilation, colon wall thickening, mucosal discontinuity, pericolonic fat stranding, extraluminal free air
Stercoral colitis: tx
bowel regimen
enemas
manua dismpaction
as long as no perf or peritonitis - if so - endoscpic guided disimpaction, consider abx or surg if perf
Radiation proctocolitis: what is this?
acute begins within 12 weeks vs chronic 8-12mo: damages rapidly growing intestinal cells, mucosa injury = loss N barrier function - inflamm = further damage
can lead to stricture, fibrosis, ischemia
Radiation proctocolitis: highest risk areas?
colon
cecum
rectum
Radiation proctocolitis: acute vs chronic dx
acute - hx
chronic - dx exclusion - endoscopy
Acute Radiation proctocolitis: management
supportive care: take to rad onc, nutrition imporvement, steroid enema?
Radiation proctocolitis: chronic management
supportive - stool softner, analgesia, antiinflamm like sulfasalazine, mesalalzine
?hyperbaric therapy shows improvement?
Neutropenic enterocolitis: what is this?
“typhlitis” - rare but important in all immunosupp with ac abdo pain
- intestinal mucosal injury typically at cecum and terminal ileum
-damage from chemo?
Neutropenic enterocolitis: u/s vs ct fndings (aside from usual neutropenic testing)
u/s in peds particularly: bowel wall thickening >0.5cm
ct - bowell wall thciekning, cecum dilation, pericolonic inflamm, pericecal fluid, pneumatosis intestinalsis, perf
Neutropenic enterocolitis: tx?
iperacillin-tazobactam (3.375 g IV, every 6 hours for adult patients, or 100 mg piperacillin/12.5 mg tazobactam per kilogram every 8 hours in pediatric patients), imipenem-cilastatin (500 mg IV every 6 hours or 1 g IV every 6 to 8 hours for adults, or 15–25 mg/kg every 6 hours in pediatric patients). Dual therapy can be used with cefepime (1g IV every 8 hours in adults, or 50 mg/kg every 8 hours) with metronidazole (1 g IV every 6 hours in adults or 30 mg/kg/day divided every 6 hours in pediatric patients). Antifungal treatment targeting candida albicans should be used in severe cases or in patients not showing any improvement after 72 hours of antibiotic treatment (fluconazole)
A 59-year-old man with a past history of diverticular disease pres- ents with his second episode of left lower quadrant (LLQ) abdom- inal pain. He is afebrile, and laboratory examination is remarkable for a leukocytosis of 13,800/mm3. Physical examination reveals moderate LLQ tenderness without masses or rebound. A com- puted tomography (CT) scan of the abdomen reveals a small (4 cm) abscess adjacent to the sigmoid colon, with moderate diverticulitis. Which of the following would be the most appropriate treatment?
a. Admission for intravenous antibiotics
b. Confirmation with double-contrast barium enema
c. Discharge on oral antibiotics with 2-day follow-up
d. Radiology consultation for percutaneous drainage
e. Surgical consultation for laparotomy
a
- What is the most common cause of large bowel obstruction in the US.?
a. Adhesions
b. Colon cancer
c. Diverticulitis
d. Intussusception
e. Volvulus
b
- Which of the following statements regarding intussusception is true?
a. Bowel obstruction typically occurs.
b. CT scans have a high sensitivity for detection of intussuscep-
tion.
c. Most adult cases involve the large bowel.
d. Most adult cases require surgery.
e. Most children have a causative lesion.
d
A 29-year-old woman presents with a 4-month history of inter- mittent abdominal pain with bloating and diarrhea. The diarrhea has been watery, nonbloody, and often nocturnal. Physical exam- ination is remarkable for mild diffuse abdominal tenderness and brown, guaiac-positive stool. Rectal examination also demonstrates a small anal fissure at the 3-o’clock position. Laboratory evaluation is remarkable only for a normocytic anemia with a hemoglobin level of 11.5 g/dL. The diagnosis would most likely be confirmed by which of the following?
a. Colonoscopy
b. CT scan of the abdomen
c. Erythrocyte sedimentation rate
d. Mesenteric angiography
e. Response to a high-fiber diet
a - IBD
5.
Which of the following statements regarding colonic ischemia is true?
a. CT scanning of the abdomen is diagnostic
b. It is rarely associated with bloody stool.
c. It is typically due to nonocclusive disease.
d. Isolated right-sided ischemic colitis is associated with compara-
tively lower mortality.
e. Specific serum biomarkers may be helpful.
c
