GI #3 Flashcards
What is the pathophysiology of chronic mesenteric ischemia?
Ischemic bowel disease due to mesenteric atherosclerosis: hypo perfusion related to eating (increased demand during eating + decreased blood supply)
Symptoms of chronic mesenteric ischemia
- Chronic, dull abdominal pain worse after meals (intestinal angina)
- Anorexia (aversion to eating) leading to weight loss
What is the definitive diagnostic test for chronic mesenteric ischemia?
-Angiography
Definitive management for chronic mesenteric ischemia
-Revascularization (angioplasty with stenting or bypass
What is the MC cause of acute mesenteric ischemia?
-Acute arterial occlusion (embolism from A-fib)
What artery is MC occluded in an acute mesenteric ischemia?
-Superior mesenteric artery
Symptoms of acute mesenteric ischemia
- Severe abdominal pain out of proportion to physical findings
- Pain poorly localized
- Nausea, vomiting, diarrhea
What is the initial test to assess ischemia for acute mesenteric ischemia?
-CT angiography
However, to get a definitive diagnosis for acute mesenteric ischemia, what should be done?
-Conventional arteriography
Treatment for acute mesenteric ischemia
- Surgical revascularization
- Anticoagulation in patients with A-fib
Ischemic colitis is
decreased colonic perfusion, leading to inflammation
What is the MC etiology of ischemic colitis
-Transient systemic hypotension or atherosclerosis involving the superior and inferior mesenteric arteries
Ischemic colitis occurs MC at watershed areas (between 2 arteries with decreased collaterals) such as the _____ and _______
splenic flexure and rectosigmoid junction
Symptoms of ischemic colitis
- LLQ crampy abdominal pain
- Bloody diarrhea
- Hematochezia
- Tenderness (not as severe and more lateral than acute mesenteric ischemia)
What is the first imaging study that is done for ischemic colitis and what does it show?
CT of the abdomen: thumb printing (segmental bowel wall thickening)
What is the treatment for ischemic colitis?
- Supportive care: restore perfusion, bowel rest, IVF
- May need empiric broad spectrum ABX, but most resolves without therapy
What type of colon polyp is the MC non-neoplastic polyp?
Hyperplastic
Pseudopolyps/Inflammatory polyps are due to
Inflammatory bowel disease (UC, Crohn’s)
What type of colon polyp is the MC neoplastic polyp?
Adenomatous polyps
How long does it take an adenomatous polyp to become cancerous?
10-20 years
Which type of adenomatous polyp is associated with the least risk?
Tubular Adenoma (MC type and least risk)
Which type of adenomatous polyp has the highest risk of becoming cancerous?
Villous adenoma
Risk factors for colorectal cancer
- Age > 50
- African Americans
- Family history of colorectal cancer
- IBD: UC > Crohn’s
- Diet (low fiber, high in red or processed meat)
- Obesity
- Smoking
- EtOH
Familial Adenomatous Polyposis is a genetic mutation of the _____ gene. Explain what happens with this condition
APC gene
Adenomas begin in childhood. Almost all develop cancer by 45 years old. Prophylactic colectomy is best for survival.
What is Peutz-Jehgers Syndrome?
Autosomal dominant condition associated with hamartomatous polyps, mucocutaneous hyperpigmentation (lips, oral mucosa, and hands), and risk of breast and pancreatic cancer
What are some protective factors for colorectal cancer?
Physical activity
Regular use of Aspirin
NSAIDs
What is the diagnostic of choice for colorectal cancer?
Colonoscopy with biopsy
Right sided (proximal) lesions for colorectal cancer tend to cause _________
Chronic occult bleeding (iron deficiency anemia, positive Guiac) and diarrhea
Left sided (distal) lesions in colorectal cancer tend to cause
Bowel obstruction, present later, and cause changes in stool diameter
Furthermore, those with a left sided (distal) lesion, may develop ______ endocarditis
Strep bovis
With a barium enema, in colorectal cancer, what is seen?
Apple core lesion
-Need a follow up colonoscopy or CT colonography
What lab abnormality is expected with colorectal cancer and why?
Iron deficiency anemia
-Colorectal cancer is the MCC of occult GI bleeding in adults
Most commonly monitored tumor marker in colorectal cancer
CEA
Management of localized colorectal cancer
-Surgical resection followed by postoperative chemotherapy
Colon Cancer Screening Guidelines
- Colonoscopy begins at age 50-75 every 10 years (average risk)
- Colonoscopy begins at 40, every 10 years (1st degree relative > 60)
- Colonoscopy begins at 40, every 5 years (1st degree relative < 60)
If a patient has familiar adenomatous polyposis, what is the screening recommendation for colonoscopies?
Initiate screen at 10-12 years with flexible sigmoidoscopy yearly
MCC of esophagitis
GERD
Pill-induced esophagitis occurs frequently with what types of pills?
Bisphosphonates, BB, CCB, NSAIDs
Infectious esophagitis is most commonly associated with _____, and some causes are ______
Immunocompromised states
Candida, CMV, HSV
Three classic symptoms of esophagitis are
Odynophagia, dysphagia, and retrosternal chest pain
What is the diagnostic of choice for esophagitis?
Upper endoscopy (allows for direct visualization)
What are the three components of pathophysiology of IBS?
- Abnormal motility: chemical imbalance in intestine (of serotonin and acetylcholine) causing abnormal motility and spasm
- Visceral hypersensitivity: lowered pain thresholds to intestinal distention
- Psychosocial interactions: altered CNS processing
Symptoms of IBS
- Abnormal pain associated with altered defecation/bowel habits
- Pain often relieved with defecation
Name three alarm symptoms of IBS
- Evidence of GI bleeding
- Anorexia or weight loss, family history of GI cancer, IBD, celiac sprue
- Persistent diarrhea causing dehydration, onset > 45 years old
What is the Rome IV Criteria in regards to IBS?
- Recurrent abdominal pain on average at least 1 day/week in the last 3 months associated with at least 2 of the following:
- -related to defecation
- -change in stool frequency
- -change in stool appearance
What is the first-line management of IBS?
Lifestyle and dietary changes (low fait, high fiber, unprocessed food diet)
- Sleep hygiene
- Smoking cessation
- Exercise
If the patient is experiencing constipation symptoms, what are some medications that can be given?
- Fiber, Psyllium
- Polyethylene Glycol
If the patient is experiencing diarrhea symptoms, what are some medications that can be given?
- Loperamide
- Dicyclomine, Hyoscyamine
