Pathology 3500 Lecture 27: Diseases of the GI Tract II
1 May 2018
School
Department
Course
Professor
PATH FEB 14
Large Bowel Anatomy
● Ascending colon
● Hepatic flexure
● Transverse colon
● Splenic flexure
● Descending colon
● Sigmoid colon
● Rectum
Diverticulum
● Medical term for an outpouching of a hollow (or fluid filled) structure in the body
● It use implies that the structure is not normally present
● Very common (about 50% of adults will have this)
● Diverticulosis: presence of diverticula
● Diverticulitis: inflammation of diverticula
Colonic Diverticular Disease Pathogenesis
● Low fiber diet lead to low volume stools (hard)
○ Bowel must contract (peristalsis) more to move feces
○ Increase in intraluminal pressure
● There are natural weak points in bowel muscle layer where blood vessels pass through
○ The increase pressure pushes the lining out of these weak points and thus you
develop diverticulums
● Appearance
○ Thicken muscle of the bowel (hypertrophy) since it is working so hard
○ Mucosa lining is pushed into the muscle
● Mostly asymptomatic on their own
● However, fecal material can get stuck in the diverticulum
○ Areas of inflammation
■ Diverticulitis
Diverticular disease Complication
● Abscess
○ Collection of pus
● Stricture
○ Fibrosis leading to bowel obstruction
● Fistular to bladder, vaginal, small bowel
○ Abnormal communication between 2 hollow organs
○ Fecal material can end up in inappropriate places
● Bleeding
● Rupture into the abdominal cavity
○ Fecal peritonitis
find more resources at oneclass.com
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Presentation
● Triad of
○ Fever
○ increase lower quadrant pain
○ Increase leukocytes (increase WBCs count)
Treatment
● Bowel rest
● Antibiotics
● Surgery
○ recurring acute attacks or complication
○ Remove the part of the bowel that is inflamed
○ For perforation and fistulas
Inflammatory Bowel Disease (IBD)
● Includes 2 conditions
○ Ulcerative Colitis (UC)
○ Crohn’s DIsease (CD)
● Peak onset 15-35 years (young adulthood)
○ Occanponal in young children, elderly
● Chronic disease
○ Cant be cured
○ Just controlled
○ Escabration and remessions
● Extraintestinal problems
○ Liver
○ Joints
○ Eye
○ Skin
● Pathogenes
○ Abnormal immune reaction to gut flora
■ In genetic susceptible people
● High concordance in identical twins (50%)
● 15% have 1st degree relative with IBD
■ Too much action of Tcel
■ Too little control by regulatory T-cells
● Crohn’s DIsease
○ Distribution
■ Not resiticture to the bowel
● Anywhere in the GI tract (mouth to anus)
○ Ulcers in the oral cavity
○ Fistulas in the anus
■ Terminal ileum and/or large bowel commonest
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
It use implies that the structure is not normally present. Medical term for an outpouching of a hollow (or fluid filled) structure in the body. Very common (about 50% of adults will have this) Low fiber diet lead to low volume stools (hard) Bowel must contract (peristalsis) more to move feces. There are natural weak points in bowel muscle layer where blood vessels pass through. The increase pressure pushes the lining out of these weak points and thus you develop diverticulums. Thicken muscle of the bowel (hypertrophy) since it is working so hard. Mucosa lining is pushed into the muscle. However, fecal material can get stuck in the diverticulum. Fecal material can end up in inappropriate places. Remove the part of the bowel that is inflamed. 15% have 1st degree relative with ibd. Anywhere in the gi tract (mouth to anus) Entire thickness of the wall is involved in the inflammatory process.
