205. Bowel Path 3: Small and Large Bowel

*Crohn Disease* Of the gross pathology of Crohn Disease, what are the features that will present with the disease (4)?

*Adhesions* *Thickened intestinal wall* ***Fistula*** *Creeping Fat*

*Crohn Disease* What are aphthous lesions?

*Aphthous lesions* are small erosions that are associated with a neutrophilic infiltrate

What is another condition that presents as follows: **Chronic watery diarrhea for months to years** *Middle aged or older patients* *Female to male 8:1* **Normal endoscopic appearance**

*Collagenous Colitis*

*Ulcerative Colitis* What is **toxic megacolon**?

*Complete cessation of colon neuromuscular activity has led to massive dilatation of the colon and black-green discoloration signifying gangrene and impending rupture.* That looks super angry... rip-roaring infection

How would you define a diverticula?

*Protrusion of mucosa and submucosa through the muscle wall*

*Crohn Disease* Of the following, what would be seen in Crohn Disease? -aphthous ulcers -esophageal ulcers -serpiginous ulcer -fissures -hairy leukoplakia -duodenal ulcers -cobblestone mucosa

*aphthous ulcers* *serpiginous ulcer* *fissures* *cobblestone mucosa*

*Ulcerative Colitis* What are the histopathological markers of UC? (4)

-*Pseudopolyps* -Sharpe demarcation between affected and non-affected areas -Coalescence of mucosal erosion/ulcers -Islands of residual mucosa

*Crohn Disease* What are the 6 histopathological features of Crohn's? (try and get the 4 bold parts)

-Non-necrotizing *granulomas* -*Transmural* lymphoid aggregates -Frequently transmural inflammation with deep ulcers (*fissures*) -*Crypt destruction/distortion* -Submucosal fibrosis -Mucosal ulcers

Flip it

-Which side is normal and which side is abnormal? -What is the abnormal called? -Left is normal, right is abnormal = **Lymphocytic Colitis**

*Crohn Disease* 1. *[Contiguous/Non-contiguous] mucosal inflammation.* 2. T or F: they get a fibrotic, patent lumen of the small intestine. 3. Will patients get perforations or abscesses?

1. ***Non-contiguous mucosal inflammation*** 2. Fibrosing **Strictures** 3. *Perforation and abscess*

*Lymphocytic Colitis(Microscopic Colitis)* 1. What is this? 2. Who does it affect? 3. M or F predominance? 4. What will appear on endoscopy?

1. **Chronic watery diarrhea for months to years** 2. *Middle aged patients* 3. *Female to male 3:1* 4. **Normal endoscopic appearance**

*Diverticular Disease* 1. What does this refer to? 2. Where is it most common? 3. Are they asymptomatic? 4. What is inflammation of the diverticula called? What brings it about? 5. Are preforations common? What can they result in?

1. **Refers to acquired pseudo-diverticular outpouchings** 2. **Most common in the sigmoid colon** 3. **>80% asymptomatic** 4. Inflammation of diverticula is called *diverticulitis* (pain, leukocytosis and fever) - ***Low Dietary Fiber, High Dietary Fat, High Dietary Red Meat*** 5. Perforation is uncommon but it can result in **pericolonic abscesses**, sinus tracts, and peritonitis Fun fact: Colonic diverticula are rare <30 yr

*Ulcerative Colitis* - Histopathology 1. *[Diffuse/Focal] inflammation* in UC characteristically is confined to where? 2. What type of abcesses are formed? what is usually destroyed? 3. What erosive and fake growths are present? 4. On biopsy, what is uniformly involved by inflammation? 5. Are there granulomas?

1. *Diffuse inflammation* in UC characteristically is confined to the mucosa 2. Cryptitis / crypt abscess and gland destruction/distortion 3. Ulcers and **pseudopolyps** 4. ***Mucosa biopsy uniformly involved by inflammation*** 5. **No granuloma**

What are the other two causes of Chronic Colitis? (2)

1. *Diversion Colitis* 2. *Graft vs. Host Disease*

*Inflammatory Bowel Disease* 1. What is it? 2. What are the 2 different types? 3. How do you tell them apart?

1. *Inflammatory bowel disease* (IBD) is a chronic condition resulting from *inappropriate mucosal immune activation*. 2. *Crohn disease and Ulcerative colitis* 3. *Distinction between ulcerative colitis and Crohn disease is based, in large part, on the ***distribution of affected sites***

*Ulcerative Colitis* 1. [Smooth/Sharp] transition between diseased and uninvolved segments of the colon. 2. Where is UC always present? 3. What condition occurs in approximately 5% of severe flares of UC?

1. *Sharp transition between diseased and uninvolved segments of the colon.* 2. ***Always involves rectum*** 3. **Toxic megacolon** occurs in approximately 5% of severe flares of UC

*Ulcerative Colitis* 1. Is the muscularus intact usually? 2. Where is the inflammation again? 3. What type of ulcers are present usually?

1. *The muscular us is intact* 2. *Intense chronic inflammation throughout the mucosa*. 3. *A broad-based flask shaped ulcer is present*

MIX AND MATCH TIME!! A. UC B. CD 1. **Extends proximally from rectum; no skip lesions** 2. **Segmental with rectal sparing** 3. **Granulomas common** 4. **Diffuse mucosal inflammation/ulceration** 5. **Does not involve ileum** 6. **Bloody diarrhea** 7. **Frequently involves ileum**

1. A 2. B 3. B 4. A 5. A 6. A 7. B

*Ulcerative Colitis* 1. What are the common sx? 2. Following the initial flare, what % of patients follow an *intermittent course* and what % follow a *chronic continuous course*?

1. Common symptoms include *diarrhea, rectal bleeding, passage of mucus, urgency, and abdominal pain* 2. Following the initial flare, 40% to 65% of patients have an *intermittent course*, and *5% to 10%* of patients have a *chronic continuous course* Fun fact: Approximately 800,000 people afflicted with ulcerative colitis in the United States

*Inflammatory Bowel Disease* 1. What one has skip lesions? 2. Continuous colonic involvement beginning in rectum? 3. Transmural inflammation, ulcerations, and fissures? 4. What about pseudopolyps and ulcers? 5. So what separates the two of them again?

1. Crohn disease 2. Ulcerative colitis 3. Crohn disease 4. Ulcerative colitis 5. Distinction between ulcerative colitis and Crohn disease is based, primarily on the *distribution of affected sites*

*Crohn Disease vs. Ulcerative ColitisComparison Summary* 1. What is the distribution of Crohn's through the colon? 2. What about UC?

1. Crohn's has skip lesions 2. UC is continuous colonic involvement beginning in the rectum Distribution of lesions in inflammatory bowel disease. The distinction between Crohn disease and ulcerative colitis is primarily based on morphology and distribution of lesions

*Crohn Disease* 1. When are most dx made (age range)? 2. Sx? 3. What areas of the bowel does it most commonly affect? 4. Risk of what cancer? by how many times?

1. Diagnosed most often among persons 15 to 30 years of age 2. Intermittent attacks of prolonged *diarrhea, fever, and abdominal pain* 3. Most commonly affects *distal ileum* and *colon*, but may involve mouth to anus Risk of GI *adenocarcinoma* is increased 5-6x

*Irritable Bowel Syndrome* 1. How is IBS characterized? 2. How many patients in GI practices have IBS? 3. What is the pathogenesis?

1. IBS is characterized by the presence of *chronic relapsing abdominal pain/discomfort* associated with changes in stool frequency or stool form. 2. In GI practices *one third of patients have functional GI disorders*, IBS being the most common diagnosis. The diagnosis of IBS rests on a careful history and physical examination. 4. **Pathogenesis unknown**

1. When does GvHD occur? 2. What are the antagonists? Which cells are being targeted? 3. How does it present?

1. Occurs following *hematopoietic stem cell transplantation* 2. *Donor T cells targeting antigens* on the recipient's GI epithelial cells 3. Intestinal graft-versus-host disease often *presents as a watery diarrhea* but may become bloody in severe cases

*Ulcerative Colitis* 1. Where is the inflammation confined to again? 2. What does this cause?

1. The inflammation is confined primarily to the mucosa 2. Undermines the surrounding mucosa and produce a *flask shaped ulceration*

*UC vs CD* Which one goes with UC and which ones goes with CD? 1. pANCA+/ASCA- 2. pANCA-/ASCA+ 3. What is the name of the antibody that marks for CD? What are they named after?

1. UC 2. CD 3. ***Anti-Saccharomyces cerevisiae antibodies --> CD*** Antibodies against antigens presented by the cell wall of the yeast **Saccharomyces cerevisiae**

*Crohn Disease* 1. What are the earliest lesions found in CD? 2. What can they turn into?

1.Earliest lesion the *aphthous ulcer* 2. May progress, and multiple lesions often coalesce into elongated, *serpentine ulcers*

*Crohn Disease* 3. What type of appearance does the mucosa have? 4. What is the definition for #1?

3. *Mucosa with Cobblestone Appearance* 4. *Anastomosing ulcers outlining islands of residual intact mucosa*

*Ulcerative Colitis* 3. Peak onset of age? 4. More common in non smokers or current smokers? 5. What other systemic disorders are associated with it?

3. Onset of disease peaks from ages 20-25 yrs 4. Ulcerative colitis is *more common among nonsmokers than among current smokers* 5. *Systemic disorder* with migratory polyarthritis, ankylosing spondylitis, uveitis and ***primary sclerosing cholangitis***

*Irritable Bowel Syndrome* 4. When is the peak prevalence? 5. M or F predominance? 6. What do you need to rule out first?

4. Peak prevalence of IBS is between 20 and 40 years of age 5. Significant female predominance 6. **Need to rule out other causes, such as enteric infection, celiac disease or inflammatory bowel disease**

*Crohn Disease* 5. When does the disease peak?

5. *Disease peaks in 2nd to 3rd decade; minor peak 6th to 7th* Here are some other cool facts (not bolded) -Primarily Western nations -Incidence 3/100,000 in US, and rising -More common in whites than blacks: Jews than non-Jews -More common in females than males (~2:1)

*Crohn Disease* 5. Where are strictures usually found?

6. ***Terminal Ileum***

*Ulcerative Colitis* 6. What is the antibody that is present? What % of patients? 7. Risk of what type of cancer? 8. Risk of #7 is greatest in what subset of UC patients?

6. ***pANCA*** autoantibody is present in 41% to 73% of patients with UC. 7. Risk of ***adenocarcinoma*** of the colon 8. Greatest in those with **pancolitis** of *>10 years duration* (20-30-fold increased risk)

*Crohn Disease* 6. What % of patients does it only affect the Ileum? 7. % that affects *small bowel and colon*? 8. *Colon* only? 9. How often does it involve the duodenum, stomach, esophagus, and mouth? 10. Is this different from UC?

6. 40% small bowel only (*Ileum*) 7. 30% *small bowel and colon* 8. 30% *colon* only 9. Rarely may involve duodenum, stomach, esophagus, mouth 10. ****This pattern of bowel involvement is different from ulcerative colitis***

MIX AND MATCH TIME!! A. UC B. CD 8. Watery diarrhea or constipation 9. Strictures are rare (5%) 10. Fistula 11. No serositis / adhesions 12. No granulomas 13. Serositis / adhesions 14. Focal inflammation and ulceration 15. No fistula

8. B 9. A 10. B 11. A 12. A 13. B 14. B 15. A

*Ulcerative Colitis* 9. Where is UC most severe in the bowel? 10. Where is the majority of the initial presentation going to be for most patients? 11. What % have the disease extend beyond the sigmoid? 12. What % have pancolitis?

9. **Severe inflammation** distally and progressively *less severe more proximally* 10. *45%* of patients with UC have disease **limited to the rectosigmoid** 11. *35%* 12. **20% of patients have pancolitis.**

Mrs. V (1980) Clinical History: Intractable diarrhea for 9 months 43 yo woman Recent weight loss Admitted to hospital for comprehensive workup

After colonoscopy, psychiatric consults, dietary restriction.... Empirically treated with ***corticosteroids*** *Her diarrhea stopped*

*Indeterminate Colitis* What is this?

Because of the extensive pathologic and clinical *overlap between ulcerative colitis and Crohn disease definitive diagnosis is not possible in approximately 10% of IBD patients.* These cases are termed **Indeterminate colitis**

Here are the learning objectives

Define Irritable Bowel Syndrome (IBS) How is IBS different from celiac disease? Compare and contrast the major types of Inflammatory Bowel Disease, Crohn Disease and Ulcerative Colitis, including epidemiology, clinical findings, major pathological findings, risk factors, associated diseases, and subsequent risk of intestinal malignancy. Define the unique features of microscopic colitis including the microscopic characteristics. Describe clinical and pathological findings in Diverticular disease.

Aaaaaaand we're done!

Every time... but i keep going back for more...

Check out these pseudopolyps

Great, huh?

Press #2

I know that we dont have to know the histology, but this is the only way to get through this section

*Crohn Disease* What is the creeping fat that is seen in CD?

In cases with extensive transmural disease, mesenteric fat frequently extends around the serosal surface (*creeping fat*)

Gracias

Press #2 please

Welcome back to the small intestine and large bowel

Seems a bit drastic, but we'll take it

What are you going to see on histology for *collagenous colitis*?

Subepithelial collagen is thickened with collagen

What is diversion colitis?

Surgical treatment --> temporary or permanent ostomy and a **blind distal segment of colon**

Do you want to see a rectum and Ileal celcal valve with UC?

There ya go

Flip it again

What do we have here? *Crypt Architectural Distortion*

Flip it one more time

What do we have here? **High grade dysplasia** *in a patient with UC*

Question on back

What do we have here? Diverticular Disease

Flip it around to the other side

What do we have here? you guessed it! Diverticular disease: colonoscopy

why you here? why you no on otha side?

What do we have here? (Pick from list) -Non-necrotizing *granulomas* -*Transmural* lymphoid aggregates -Frequently transmural inflammation with deep ulcers (*fissures*) -*Crypt destruction/distortion* -Submucosal fibrosis -Mucosal ulcers -*Granuloma*

You can look on the other side of this card and see a histology slide that will then help you answer the question that is on the other side of this card because it isnt on this side of the card because we cant get pictures on the front of the cards because Quizlet is run by the Illuminati

What do we have here? Describe what you see Lymphocytic colitis Intraepithelial lymphocytes

Flip it

What is this? Crypt abscess