Small Intestine/Colon Path 2+3 - Nelson Flashcards
Why is ulcerative colitis often considered a “left-sided” disease of the colon?
ALWAYS begins int eh rectum and can then extend proximally all the way to the cecum, usually does not involve the whole colon
What is the difference between the wall involvement in UC vs CD?
UC affects the mucosa and submucosa only. Whereas CD has transmural involvement - full thickness inflammation with knife-like fissures
What locations int he bowel does CD affect?
Can be anywhere from mouth to anus. Terminal ileum is most common, rectum least common.
SKIP LESIONS - not continuous like UC
How do symptoms differ between UC and CD?
UC -
LLQ pain, bloody and mucus-ey diarrhea with tenesmus and rectal inflammation
CD -
RLQ pain, mild non-bloody diarrhea, symptoms variable
How does smoking affect risk for UC and CD?
UC - smoking is protective
CD - smoking increases risk
You are looking through a microscope at a specimen of bowel from a pt with IBD. You see crypt abscesses with neutrophils and lymphocytes.
UC or CD?
Ulcerative Colitis!
How do you differentiate ASCA and pANCA using UC and CD?
pANCA = UC ASCA = CD
What is the classical gross appearance that you see in Crohn’s disease?
Cobblestone mucosa! (Remember: That old Crohn walking down the cobblestone street) Strictures causes by wall hypertrophy! Creeping fat! Patchiness!
What are the worrisome complications of UC and CD?
UC
- Toxic Megacolon
- Risk for dysplasia —> adenocarcinoma
CD
- Malabsorption
- Fistula formation to bladder, rectum, between bowel, etc
- Carcinoma in colon
- Obstruction (from strictures)
a 30 yr old patient of yours has had a fairly recent surgery to form a diverting ostomy. He begins experiencing diversion colitis. What is the patholgical cause behind this problem?
The blind segment of colon is not longer receiving stool. This causes this part of the bowel to have a deficiency in short chain fatty acids
Tx with return of fecal stream or enemas containing SCFA’s
In a patient undergoing radiation therapy for prostate cancer, what might you be worried about in his Gi tract?
radiation enterocolitis
Can be MISDIAGNOSED as dysplasia, looks just like it, but will return to normal faster and doesn’t have the same risk of cancer
Feeding a premie baby orally is a bad idea why?
Neonatal necrotizing enterocolitis can occur.
Occurs in 1st week of premature infant life while their GI defense are impaired
- Small and large bowels exhibit transmural necrosis
- air bubbles form in intestinal wall
Which class of drug in commonly implicated in drug-induced enterocolitis?
NSAIDS
chemo agents can cause ulcers in entire Gi tract
Use like 2 sentences to describe irritable bowel syndrome:
Chronic, relapsing, abdominal pain, bloating, and either diarrhea or constipation WITHOUT any known cause.
There are no pathologic changes seen and symptoms often improve after defecation
What’s the difference between diverticulosis and diverticulitis?
Diverticula are outpouching of mucosa (not true diverticula) often located in the sigmoid colon.
Mutliple diverticula make diverticulosis
Diverticulitis occurs when they become inflamed, often with bacteria
Malfunction of the puborectalis muscle can lead to excess straining on defecation and rectal prolapse. Inflammatry polyps and ulcerations then form on the anterior rectal wall.
What is this syndrome called?
Solitary rectal ulcer syndrome
When you first started learning about polyps, you thought a juvenile polyps were rebellious polyps that enjoyed staying out late and not cleaning their rooms.
Now you understand this was a terrible joke from a medical student friend of yours. So what is it really?
Call it juvenile because it happens in kids and adults (most common that you see in kids)
It’s a hamartomatous polyp, which means it’s made of a disordered collection of normal tissue. Can sometimes cause rectal bleeding
A 12 year old boy presented with intussusception and Gi bleeding. After resolving the intussusception, colonoscopy and capsular endoscopy revealed numerous polyps in the large and small intestine. The polyps were found to be hamartomatous and the patient has a strong family history of cancer. You also notice the boy has some odd mucocutaneous hyperpigmentation….
What is the diagnosis?
Root cause?
Peutz-Jegher’s Synrome
Caused by autosomal dominant loss of STK11 tumor suppressor gene
Name of the most common adult, usually harmless polyp?
Hyperplastic polyp
What is melanosis coli?
Colon mucosa is brown. Lipofuscin-like pigment is deposited in macrophages
What is lymphomatosis polyposis?
Mantle cell lymphoma in colon. Results in tumor cells with irregular nuclear contours
What is the general pathophysiology behind acute appendicitis?
- Obstruction
- Venous outflow compromised by intraluminal pressure
- ischemic injury occurs
- Accute inflammation
Typical clinical presentation for appendicitis?
Periumbilical pain localized in RLQ with tenderness over McBurneys point
Pain-induced nausea/vomiting
What are anal hemorrhoids?
Anal varices from ectasia of rectal venous plexus due to elevated venous pressure
Caused by straining, pregnancy, prolonged sitting
What exactly is an anal fissure?
Linear separation of tissue of anal canal through the mucosa. Caused by firm stools
90% are posterior
What virus is associated with Anal Carcinoma?
HPV
most common type is squamous cell carcinoma
