Definitions
- Diverticulum – abnormal out-pouching or sac of the colon wall
- Diverticulosis – is the condition of having multiple acquired diverticula in the colon that are not inflamed
- Diverticulitis – acute inflammation of diverticulum
Congenital diverticula
- Distinguished from acquired type by being composed of ALL layers of bowel wall
- Most are ‘true’ diverticula
- E.g. Meckel’s diverticulum – remnant of vitello-intestinal duct
- Common in caecum – presents with bleeding, anaemia, melena
Acquired diverticula
- Usually composed of mucosal layer and do not involve the muscular or adventitial layer
- They are usually pulsion in nature
- Implies that the mucosal lining of the colon has been forced out through a defect
- Most are ‘false’ diverticula
Etiology
- Most common in countries where dietary fibre is deficient
- Poor diet → contractions of colon are more vigorous and prolonged → raises intraluminal pressure → leads to herniation of the mucosa through the circular muscle of the colonic wall
- Most common in females 40-50yo
Pathology
- Diverticula mainly found in the sigmoid colon – as it’s the narrowest and has the highest intraluminal pressure
- Emerge between the taenia coli and may contain faecoliths
- Circular muscle of the colon is thickened – causes shortening of colon
Clinical features
- Fatigue, lethargy
- Fullness of abdomen, bloating, flatulence
- Light headedness and shortness of breath – due to anemia
Complications
- Painful diverticulosis
- Acute diverticulitis – left lower quadrant pain
- Perforation of diverticulum – can cause faecal peritonitis
- Obstruction – from fibrosis
- Fistula (colovesical/colovaginal) – discharge of faecal matter through vagina
- Haemorrhage – in elderly patients without warning
Investigations
- Diverticulosis – barium enema (colonoscopy). Do not perform during acute attack (perforation)
- Diverticulitis – FBC, WCC, U+Es, CXR, CT
- Perforation – abdominal XR + CT
- Obstruction – gastroffin/dilute barium enema, colonoscopy to exclude malignancy
- Colovesical fistula – midstream urine, cytoscopy, barium enema
- Colovaginal fistula – colposcopy, flexible sigmoidoscopy
Treatment
- Asymptomatic diverticulosis – doesn’t require treatment
- Symptomatic – high fibre diet
- For treatment of complications – see Diverticulitis