Acute Diverticulitis: Pathogenesis and clinical findings Low fiber diet
Authors: Candace Chan Yan Yu Wayne Rosen* Reviewers: Laura Craig Noriyah AlAwadhi Danny Guo Erica Reed Maitreyi Raman* Claire Song Shahab Marzoughi * MD at time of publication
↓ Colonic motility
↑ Stool transit time Formation of small dry stool
Stool build-up and ↑ strain with bowel movements
↑ Pressure in the colonic lumen
Constipation (difficulty passing stool)
Obstipation (inability to pass any feces)
Inherent weakness in the muscle layers of the colonic wall associated with immature collagen fibers and diminished wall elasticity
Mucosal and submucosal layers of the colon wall push through a weak spot of the circular muscle layer
Formation of diverticulum (sac-like protrusion of the colonic wall)
Continued stress on diverticula causes micro- perforations of the diverticulum
Inflammation of diverticula
Mesentery and pericolic fat (fat surrounding the colon) attempt to wall off inflammation or perforations
Stool bacteria escapes the colon
Formation of abscess (accumulation of pus in response to the bacteria )
Pro-inflammatory cytokine release from nearby adipose tissue
Hypothalamic thermoregulatory center increases core temperature set point
Fever
Irritation of parietal peritoneum
Inflamed vessels are more permeable and fluid leaks from colonic vessels into the abdominal cavity
Chronic low-grade inflammation triggers activation of pro-fibrotic factors and fibroblasts
Excess production of extracellular matrix proteins
Stimulation of somatic nerves sends pain signals to the brain
Lower left quadrant abdominal pain
Peritoneal signs (abdominal guarding, rigidity, rebound tenderness)
↓ Total circulating blood volume
↑ heart rate
↓ Jugular venous pressure
Orthostatic hypotension (low blood pressure when standing after sitting/lying down)
Gastrointestinal strictures and/or colonic obstruction
Accumulation of micro- perforations further weakens intestinal wall
Complete bowel perforation (medical emergency)
Development of an abnormal connection (fistula) through the bladder, vagina, skin, or gut
Abscesses
Accumulation of fibrotic tissue narrows the intestinal lumen
Fibrosis of colon
Legend:
Pathophysiology
Mechanism
Sign/Symptom/Lab Finding
Complications
Re-Published Oct 4, 2024 on thecalgaryguide.com