Miscellaneous GI Disorders Flashcards
What are some potential contributers to the pathogenesis of IBD?
- Psychologic stressors
- Diet
- Abnormal GI motility
- Visceral hypersensitivity
- Nervous system interprets normally benign signals as painful
- How common is IBS?
- What is the typical age range when IBD manifests?
- Is there a male or female predominance?
- 5-10%, in developed countries
- 20-40 years old
- Significant female predominance
What is a type of IBS that arises secondary to another GI condition?
Post-infectious IBS
Continued GI sxs following a GI infection
IBS
- What lab findings are typical in IBS?
- What endoscopic findings are typical in IBS?
- What CT findings are typical in IBS?
IBS
- Normal (CBC, electrolytes, LFTs)
- Normal
- Normal
The point is that IBS has a diagnosis of exclusion.
What set of criteria is used to diagnose IBS?
Can you describe the criteria generally?
[It was stated we would not be held responsible for the specifics]
Rome III Criteria
- Recurrent abdominal pain / discomfort associated with:
- Improvement with defecation
- Onset associated with change in frequency or appearance of stool
[This is a simplification of the criteria]
Where in the GI tract does Diverticular Disease occur?
Why is the name “Diverticular Disease” a bit of a misnomer?
Most often the sigmoid colon, but can be any region of the colon
The outpouchings are technically pseudodiverticular, as they only involve the colonic mucosa and submucosa.
- What about the structure of the colonic wall allows for the development of Diverticular Disease?
- What preventable risk factor is thought to contribute to the development of the disease?
- The colonic muscularis propria has discontinuities where nerves and arterial vasa recta penetrate the inner circular muscle layer. Repeated conditions of high intraluminar pressure can cause herniation of the mucosa and submucosa through the discontinuities, creating diverticuli.
- A low fiber diet is throught to stress the colon, necessitating strong contractions to expel the relatively less bulky stool. This leads to repeated high intraluminar pressure, as mentioned above.
What are the demographics of diverticular disease?
- Rare in persons < 30 years old
- Prevalence up to 50% in Western adult populations age > 60
What are some complications of Diverticulosis?
-
Diverticulitis (inflammation due to obstruction and bacterial flourishing)
- Perforation
- Pericolonic abcesses
- Development of sinus tracts
- Peritonitis
- Perforation
What is a sinus tract?
How does it differ from a fistula?
The two are pretty similar. From what I gather:
- Sinus tract
- An abnormal tunnel that forms to drain a fluid-forming (suppurative) wound to a cutaneous or mucosal surface
- Fistula:
- An abnormal tunnel that forms between two cutaneous or mucosal surfaces
What is the most common presentation of Diverticular Disease?
Most cases are asymptomatic!
When it does have symptoms (~20% of cases):
- Intermittent cramping
- Continuous lower abdominal discomfort
- Constipation
- Diarrhea
How are Diverticular Disease and Diverticulitis treated?
- A high fiber diet can prevent diverticulitis
- Diverticulitis often resolves spontaneously or after antibiotics
- A few pts require surgery
What are the demographics for appendicitis?
- Most common in adolescents and young adults
- May occur in any age group
- Males > Females
- Lifetime risk 7%
What is found to be the origin of appendicitis in the majority of cases?
-
Overt luminal obstruction
- Often a stonelike mass of stool (fecalith)
- Causes ischemic injury & stasis of contents
- Favors bacterial proliferation
- Inflammation
The deep tenderness noted at 2/3 the distance from the umbilicus to the right anterior superior iliac spine is referred to as _ _’s sign.
McBurney’s Sign
(The aforementioned location is likewise called McBurney’s Point)
What is the typical presentation of appendicitis?
- Periumbilical pain that “moves” to the right lower quadrant
- Nausea & Vomiting
- Low-grade fever
- Mildly elevated WBC count
Ischemic Colitis
- What is the usual cause of a mucosal infarction?
- What is the usual cause of a transmural infarction?
- Mucosal: hypoperfusion
- Hypotension
- Arterial spasm
- Transmural: arterial occlusion
- arterial thrombosis or embolis
What parts of the intestines are particularly susceptible to ischemia?
- Intestinal segments at the end of their respective arterial supplies
- “Watershed Zones”
- Splenic flexure
- Sigmoid colon and rectum
- Sometimes the right colon
True or False: Ischemic Colitis typically is segmental and patchy in its distribution.
True.
How does the mucosa appear in ischemic colitis?
Hemorrhagic and often ulcerated
How is ischemic colitis treated?
- Resolve the inciting event (e.g. hypotension)
- Usually self-limited
What age group is ischemic colitis most common in?
What are the risk factors?
Older persons
Cardiac or vascular disease
How does an acute transmural infarction of the colon typically present?
- Sudden severe abdominal pain & tenderness
- Sometimes accompanied by:
- Nausea & Vomiting
- Bloody Diarrhea
- Grossly melanotic stool
- Generally, how does the bacterial population of the small intestine differ from that of the colon?
- What protects the small intestine from bacteria?
- The small intestine is relatively sterile compared to the colon.
- Gastric acid at the proximal end and the ICV at the distal end; relatively fast travel of contents
What are three more common causes of small intestinal bacterial overgrowth?
- Surgery
- Antacid
- Slow mobility
A small intestinal bacterial overgrowth can be difficult to diagnose. What are two useful tests?
- Duodenal aspirate
- Hydrogen breath test
What is the hallmark symptom of microscopic colitis?
Chronic, watery, nonbloody diarrhea
What are the two subtypes of microscopic colitis?
- Collagenous colitis
- Lymphocytic colitis
What findings turn up normal in both subtypes of microscopic colitis?
- Radiologic studies
- Endoscopic studies
What are the two characteristic findings in collagenous colitis?
How does this differ from lymphocytic colitis?
- Collagenous
- Presence of a dense subepithelial collagen layer
-
Increased intraepithelial lymphocytes
- plus a mixed inflammatory infiltrate within the lamina propria
- Lymphocytic
- Increased epithelial lymphocytes
- Normal subepithelial collagen layer
Who does collagenous colitis typically affect?
Who does lymphocytic colitis typically affect?
- Collagenous: middle-aged and elderly women
- Lymphocytic: associated with celiac disease and other autoimmune diseases
What are possible GI symptoms of Graft-Versus-Host Disease?
- Nausea
- Cramping
- Watery diarrhea
How does Graft-Versus-Host Disease that is affecting the small intestine or colon appear histologically?
- Epithelial apoptosis, especially crypt cells
