GI - Bowel Flashcards
What are the two types of bowel obstruction?
Mechanical
-blockage of bowel lumen
-small bowel distended
-bowel sounds PRESENT
paralytic ileus
-failure of peristalsis
-gas distributed throughout small and large bowel
-NO bowel sounds
-generally occupies the more central portion of the abdomen
-dilated small bowel loops
-air/fluid levels
-lack of gas in colon
Small bowel obstruction
-positioned laterally around the periphery of the abdomen or inferiorly in the pelvis
-carcinomas mostly
-diverticulitis
-volvulus
-large dilated colon
-gas filled loop of small and large bowel
-distal colon usually free of air (collapsed)
-non-dilated small bowel loops
Large bowel obstruction
*less acute than SBO, develops slower and less gastric disturbance
-intestinal motility becomes inhibited
-fluid and gas do not pass normally through NON OBSTRUCTED bowel
-seen with large amounts of gas and fluid in the small and large bowel with no obstruction
Ileus
What are the 2 types of ileus?
Localized
-isolated distended loops of small/large bowel
-often associated with acute inflammatory process
Colonic
-disproportionate distension of large bowel without obstruction
-follows acute inflammatory process or abdominal surgery
-twisting of the stomach or bowel upon itself (180)
-severe abdominal pain
-can cause blood vessel compression or bowel obstruction
Volvulus
Where does volvulus most commonly occur?
Adults - sigmoid colon
Children - small bowel
*can also occur in the stomach and cecum
*more common in children
How does volvulus appear on an image?
-distended bowel loops
-no gas in colon/large bowel
Barium study
Cecal volvulus - fills colon to distal cecum
Sigmoid volvulus - coffee bean/birds beak appearance
-babies intestine does not form or rotate in the correct way
-can be asymptomatic unless volvulus occurs
Malrotation
*imaging will show incorrect placement of bowels
-part of the intestine slides into the other part
-telescoping
-can cause blockages of fluid, food, blood
-usually in children
Intussusception
*most commonly occurs at the iliocecal valve
*donut shaped on US
The physical outpouchibg of the bowel
Diverticulum
Diagnosis of 1 or more diverticula
Diverticulosis
Inflammation of infected diverticula
Diverticulitis
Where does diverticulitis most commonly occur?
Large bowel, specifically the sigmoid colon
*40 years +
-inflammatory disease of the intestines, especially colon and ileum
-can affect anywhere on the GI tract
-can lead to obstructions, abscess formation, and decreased absorption
Crohns disease
How does Crohn’s disease appear on imaging?
-irregular thickens mucosal folds
-terminal ileum/proximal colon
-cobblestone appearance (high and low densities)
-string sign, skip lesions
-ulcerations
T/F
There is no cure for Crohn’s disease
True
-inflammatory disease
-young adults
-affect mucosal layer of large bowel
-usually rectosigmoid are
-increases risk of colon cancer
Ulcerative colitis
What is the difference between ulcerative colitis and Crohn’s?
Crohn’s
-can affect any part of GI tract
-all layer of lining of bowel may be inflamed
Colitis
-only affects large intestine
-only inner lining of bowel is inflamed
How is ulcerative colitis presented radiographically?
-deep ulcers in mucosa, loss of haustra markings
-continuous lesions (unlike Crohn’s - skipped lesions)
-large bowel appears “lead pipe colon”
-serious complication of ulcerative colitis
-extreme dilation of a segment of colon with systemic toxicity
-can lead to spontaneous perforation (and irreversible shock)
-can also occur in patients with inflammatory bowel disease, but less common
Toxic mega colon
*primarily affects transverse colon
T/F
Barium studies are contraindicated for toxic megacolon because of the chance of perforation
True
What is the 3-6-9 rule?
A method of describing normal bowel caliber
Small bowel - <3cm
Large bowel - <6cm
Cecum - <9cm
T/F
Long time Ulcerative colitis predisposes the patient to colorectal cancer
True
