Diverticulosis is a disease of the disgestive tract:
Pathophysiology of diverticulosis
1) outpouching of bowel wall
2) four types – Meckel’s, colonic, jejunal, and duodenal
3) colonic diverticula are acquired – likely owing to lack of fiver and increased luminal pressure as colon pushes against hard, small stool
Signs and Symptoms
Meckel’s
1) bleeding
2) inflammation
3) obstruction
4) right lower quadrant pain
Colonic
5) left lower quadrant pain
6) rebound and/or guarding secondary to microperforation and abscess formation
7) massive lower GI bleeding (erosion into nutrient artery)
8) diarrhea and/or constipation
9) fever
Jejunal
10) can act as lead edge of intussusception
Characteristic Test Findings
Radiology
1) barium enema and CT scan best diagnostic tests for colonic
2) upper GI swallow best diagnostic test for duodenal type
3) technetium nuclear medicine scan best diagnostic test for Meckel’s type
Laboratory
4) increased WBCs in colonic type
Histology/Gross Pathology
Congenital
1) Meckel’s duodenal, and jejunal types – all layers of bowel wall are affected
Acquired
2) Colonic type – mucosa outpouching through muscularis (on antimesenteric side) at site of entry of nutrient artery
3) duodenal diverticula arise from medial edge and are single
Meckel’s
4) lining can be ileal, duodenal, gastric, pancreatic, or colonic mucosa
Associated Conditions
1) bladder and vaginal fistual in perforated colonic type
2) adult polycystic kidney disease
Inheritance/Epidemiology
1) most common congentital type is Meckel’s
2) colonic occurs in 20-50% of USA adults > 50 years (more common on left side)
Treatment
Meckel’s
1) resection if symptomatic
2) possible resection if found incidentally under age 20 years (controversial)
Colonic
3) more conservative treatment recently as compared to earlier indications for surgery
4) resection of bowel segment if complication occurs – bleeding, perforation, abscess
5) if inflammation only – bowel rest, IV fluids, and antibiotics with consideration of elective resection if multiple episodes
Tips for USMLE
1) Meckel’s – think rule of twos: 2% of population; 2 cm across; 2% become symptomatic; 2 feet from ileal-cecal valve
2) Meckel’s is remnant of omphalomesenteric valve
3) both Meckel’s and right-sided colonic types can mimic appendicitis
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