25. Conference 3 Flashcards
If I have a patient and I’m not sure if they have IBS or IBD, what areas should I focus on with the physical exam?
abdomen, mouth, rectal, skin, joints
IBS: what is the pathophysiology?
Irritable bowel syndrome is a functional gastrointestinal disorder.
We cannot identify an organic reason that accounts for the patients’ symptoms.
More specifically, no structural, biochemical, or metabolic disorder can be identified that accounts for the patient’s complaints of **abdominal pain, bloating, constipation, or diarrhea. **
What are the Rome III criteria for IBS?
A chronic disorder of abdominal pain or discomfort
- present for at least 3 days per month during the previous 3 months with at least 2 of the following 3 features:
- abdominal pain/discomfort relieved with defecation
- onset associated with a change in stool frequency
- onset associated with a **change in stool consistency. **
We don’t know what causes IBS exactly, but what is the theory?
IBS is a complex disorder in which a number of physiologic processes are involved. These include abnormalities in intestinal motility, alterations in visceral sensory function, and changes in central nervous system processing of sensory information.
The realization that the gut and the brain are intimately connected now plays a central role in the theory of IBS. This interplay between the CNS and the GI tract has been labeled the brain-gut axis.
How is IBS diagnosed?
It’s not a dx of exclusion, and it’s not all in the patient’s head!
History: abdominal pain and altered bowel habits.
Intermittent symptoms (but abd pain at least 3 days out of 3 months)
Abdominal pain must be temporally related to defecation.
What are red flags concerning abdominal pain and changed bowel habits?
Weight loss, anemia, heme-positive stool, GI bleeding
fatigue, myalgias, arthralgias, fevers, chills, and night sweats
…. all concerning.
IBS: what are the physical exam findings?
Generally normal.
May be some tenderness in lower abd, some stool palpable in sigmoid colon.
There should not be rebound, guarding, perirectal fissures
There may be slight rectal tenderness but a LOT of rectal tenderness suggests some other disease.
IBS diagnosis: what tests should be done?
CBC, ESR, TSH (if constipation, to exclude hypothyroid)
Stool samples to check for bacteria, WBCs
Serology for Celiac
Sigmoidoscopy (younger patients, rectal bleeding) or colonoscopy (if > 50 or family hx of CRC)
IBS: treatment?
Primarily symptom relief.
Reassurance
Meds aimed at the underlying pathophysiology of altered GI motility, visceral hypersensitivity, and CNS modulation.
For constipation: increased fiber intake or supplement
For diarrhea: Loperamide, TCA antidepressants (remember brain-gut connection)
For abd pain: smooth muscle anti-spasm meds (anecdotal evidence only); anticholinergics; TCAs; analgesics (should be used minimally)
How do you distinguish benign (self-limited) diarrhea from medically important diarrhea?
(Consider signs of toxicity, illness duration, epidemiology, host factors)
-Illness severity: signs and symptoms of toxicity (high fever, volume depletion, severe abdominal pain) REQUIRES PROMPT EVALUATION
-Illness Duration: lasting more than 4 to 5 days indicates a more virulent organism (or other non-infectious cause) which may require specific therapy
-Epidemiologic setting: recent travel, recent food or water ingestion, swimming in public places, nursing home/day care residents, others ill, recent antibiotic use
-Host factors: immune competence
What is a good differential diagnosis for a patient who had macaroni salad and went swimming at a recent outdoor picnic…
Hx: 3 days of non-bloody diarrhea, abd cramps, nausea. Recent antibiotic usage for resp tract infection.
PE: Abd is mildly, diffusely tender, active bowel sounds. Afebrile, orthostatic instability.
- Food poisoning: C. perfringens, Salmonella, Shigella, E. coli, Campylobacter
- Giardia (contaminated swimming water)
- Clostridium difficile (antibiotic use)
- Non infectious causes (irritable bowel syndrome, inflammatory bowel disease)
What microbes are you likely to pick up at a daycare center?
Shigella, Campylobacter, Giardia, C difficile
What microbes might you pick up if you are hospitalized or have recent antibiotic use?
C diff
What microbes might you pick up in a swimming pool?
Giardia, cryptosporidium
What microbes might you pick up with foreign travel?
Toxigenic E. coli, Shigella, Giardia, E. histolytica
(no identifiable pathogen in 20-40%)
What is this nastiness?
What would we see on biopsy?
Crohn’s
Note inflammation, white exudate (this doesn’t wash off) –> ulcerations (somewhat like apthous ulcers in mouth)
Biopsy: will see granulomas
Review: what are distinguishing features of Crohn’s?
(from bottom to top…)
- Perianal disease
- Rectal sparing
- 30% with gross bleeding
- Skip lesions
- Endoscopic features: white exudates, cobblestoning
- Strictures
- Granulomas on biopsy
- Focal lesions
- Fistulas
- Involvement of entire GI, from mouth to anus
Crohn’s: anatomic distribution?
Terminal ileum = most common
Crohn’s disease: early presenting symptoms?
(local v systemic?)
Inflammation
- inflammation in the ileocecal region in 75-80% of cases
- most frequent early presentations are with local symptoms of right lower quadrant abdominal pain, tenderness, and diarrhea
- frequently with systemic manifestations of low-grade fever, anorexia, and weight loss.
Crohn’s: transmural involvement leads to obstruction – which leads to what symptoms?
- transmural inflammation produces fibromuscular proliferation. Collagen deposition in the wall of the intestine –> narrowing obstructive symptoms
- Symptoms of partial obstruction are most evident after meals, when luminal distention leads to cramps.
-Vomiting is the result of high grade obstruction.
In Crohn’s, if 2 areas of inflammed bowel are next to each other, what happens? What are the consequences?
FISTULIZATION
- penetrating ulceration through the intestinal wall, culminating in sinus tracts and fistulae to adjacent structures.
- Clinical symptoms depend on the location of the fistula.
In what situation will Crohn’s mimic appendicitis or diverticulitis?
CONFINED PERFORATION
-Localized microperforation in the ileocecal or sigmoid areas may produce acute right or left lower quadrant signs and symptoms mimicking appendicitis or diverticulitis, respectively.
Why does Crohn’s sometimes present with perineal fistulae and abscesses?
PERIANAL FISTULAE AND ABSCESS
- Separate from abdominal fistulae; disease often arises from the crypts of Morgagni in the anus and spreads through the internal sphincter muscle –> intersphincteric abscess, ischiorectal abscess, supralevator abscess, and/or rectovaginal or perineal or buttock fistulae.
- As many as one-third of patients with Crohn’s disease may have a history of anorectal fissures or fistulae or perianal abscesses.
What extraintestinal manifestations occur with Crohn’s?
Apthous ulcers, uveitis, arthritis, vasculitis, erythema nodosum, pyoderma gangrenosum.
The anterior uveitis of Crohn’s (also episcleritis) often occurs in patients with what types of arthritides?
Associated with what HLA?
Episcleritis (left panel), with injection of the deep ciliary vessels, tends to parallel the activity of the bowel disease.
Anterior uveitis (right panel), which is often painful and presents with synechiae and opacity in the anterior chamber, follows an entirely independent course;
Anterior uveitis very often clusters with spondylitis and sacro-iliitis and is usually associated with HLA-B27.
Crohn’s: describe the peripheral arthritis that can occur
This peripheral arthritis can occur with both Crohn’s and UC (according to Pathoma)
Rheumatoid pattern but with the 6 items mentioned on the slide:
One of these is erythema and the other is pyoderma gangrenosum.
Which is which, and which is associated with UC v Crohns?
Left = erythema nodosum - Crohn’s
Right = pyoderma gangrenosum - ulcerative colitis
Primary sclerosing choleangitis: more of an UC thing or a Crohn’s thing?
Ulcerative colitis.
Drug treatment for IBD in general?
Corticosteroids
budesonide (different type of steroid)
Crohn’s: antibiotics, immunomodulators (6-mercaptopurine, azathioprine, methotrexate, cyclosporine, anti-TNF )
Chronic constipation patient: what is a study you can do?
Sitz marker studies.
L panel: normal bowel
Middle: slowed colonic inertia, capsules throughout colon
Right: functional outlet obstruction
More pics of Sitzmark studies:
Below = normal and slow
Below:
abnormal study, markers all still in right colon after 120 hours.
