SI path_IBS & others Flashcards
___a___ of 5HT would lead to diarrhea.
___b___ would lead to constipation or an alternating pattern.
a) Decreased reabsorption
b) Desensitization
What is Visceral Hypersensitivity?
Lower threshold for visceral pain
somatic pain threshold remains normal
Subtle form of gluten intolerance may present as _____ without overt signs of celiac disease
IBS
T or F? Small bowel is normally in a constant state of inflammation.
True
Inflammatory cells increased in patients with severe IBS
Possible inflammatory pathology in severe IBS?
Possible lymphocytic infiltration of the myenteric plexus with neuron degeneration in severe IBS
Brain imaging studies demonstrate altered brain response in patients with IBS
– Activation of the ________ (area that processes visceral signals) after delivered or anticipated rectal distention
mid-singulate cortex
3 subtypes of IBS?
- IBS-D
- - Diarrhea predominant - IBS-C
- - Constipation predominant - IBS-M
- - Mixed
- patients may switch subtypes long-term
Rome III Criteria for IBS diagnosis?
Recurrent abdominal pain or discomfort at least 3 days/month in last 3 months, ass’d w/ 2 or more of the following:
- Improvement w/ defecation
- Onset ass’d w/ a change in frequency of stool
- Onset ass’d w/ a change in form/appearance of stool
No red flags!
What are some red flags that would rule out IBS?
- Blood in stool
- Fever
- Onset >50 yrs.
- Noctural symptoms
- Progressive dysphagia
- Weight loss
- Abdominal mass
- Malabsorption
Diagnosis?
- Onset 15-35 yrs.
- Bloody diarrhea w/ mucus, fever, abdominal pain, tenesmus, weight loss
Ulcerative Colitis
Diagnosis?
- Onset ages 25-35 or 70-80 yrs.
- Fever, abdominal pain, weight loss, diarrhea, fatigue, anorectal fissures, fistulae, abscesses
Crohn’s Disease
Diagnosis?
- Chronic diarrhea w/ or w/out blood & mucous
- Dx via microscopy, stool sample, sigmoidoscopy
Infectious Diarrhea
Diagnosis?
- Left, lower abdominal pain, fever, altered bowel habits
Diverticulitis
Diagnosis?
- Age 50 or older
- Rectal bleeding, altered bowel habits, abdominal or back pain, anemia, occult blood in stool, weight loss
Colorectal malignancy
Medications whose side effects may be confused w/ IBS?
Antacids Laxatives SSRIs Thyroid hormones Metformin Narcotics CC-blockers Anti-cholinergics
New patient meeting Rome criteria for IBS & does not have any alarm symptoms. What is next step?
Screen for Celiac’s disease.
If negative, then start first-line therapy for IBS (mainly just symptomatic)
Most important “surface enhancer”?
Villi
T or F? You should not normally see any inflammatory cells in the villi of the small intestine.
False. Normally see 5-7 inflammatory cells in the villi of the SI.
Any increase beyond this may be diagnostic of Celiac Disease.
Where are the stem cells located in the SI?
What other cells do you see here?
Crypts of Lieberkuhn
also see Paneth cells, Neuroendocrine cells, & Goblet cells
When there is mucosal injury, the ________ thickness increases relative to the _______.
Crypt (of Lieberkuhn) thickness increases relative to the villi
- Normal villi:crypt thickness is 3-5:1. Pathologic can be 1:1
(ex: seen in Celiac Disease)
- Normal villi:crypt thickness is 3-5:1. Pathologic can be 1:1
What portion of the GI tract would an Annular Pancreas obstruct?
2nd or 3rd portion of Duodenum
Tx possibility of Omphaolcoele? Gastroschisis?
Omphalocoele (visceral herniation into membranous sac)
– Surgical repair
Gastroischisis (involves all wall layers from peritoneum to skin)
– Often non-operable
Diagnosis?
Partial persistence of proximal vitelline duct.
Meckel Diverticulum
Viteline duct – connects fetal intestine to yolk sac
(usuall in Ileum)
Meckel Diverticulum - Rule of 2?
- 2% of population have them
- 2 inches long
- 2x more prominent in Males vs. Females
- 2 types of heterotropic epithelium
- – Gastric & Pancreatic
- Symptomatic by 2 yrs.
T or F? Most Meckel diverticulae are symptomatic
False, most are asymptomatic (>95%)
Intestinal scalloping is seen in what condition(s)?
Celiac Disease & Crohn’s Disease
flattening of intestinal villi
Major distinguishing histologic factor of Early vs. Late phase Celiac Disease?
Early – still see Villi
(though there’s thickening of Crypts & inflammation)
Late – complete/almost complete flattening & no longer can see Villi
(looks more like colon)
Diagnosis?
- Multiorgan disease of GI, CNS, & joints
- Caused by Gram-positive actinomycete that proliferates w/in Macrophages
- More often in Males btwn 40-50
Whipple’s Disease
(
Infectious agent that has similar histologic finding to Whipple’s Disease, however different macroscopic presentation & AFB+
Mycobacterium avii
commin in AIDS populations
How to differentiate btwn Whipple’s Disease & Mycobacterium avii
Mycobacterium avii is AFB+
Infectious agent that presents similar to Crohn’s Disease w/ fistulae, fissuring, ulcers, etc.?
Yersinia enterocolytica
Infectious agent that presents w/ intraluminal, crescent-shaped, basophilic protozoa?
Giardia lamblia
Clinical manifestations (4) of intestinal obstruction? Tx?
- Abdominal pain
- Distention
- Vomiting
- Constipation
Tx: usually requires surgical intervention
Ischemia to the intestines caused by arteritis/purpuric conditions, would be characterized by what type of tissue damage seen on histology?
Fibrinoid necrosis
