Colonic diverticular disease

Introduction

Colonic diverticular disease is very common in developed nations, which is related to their diet containing low dietary fibers.
It is estimated that in developed countries, there are about 60% of the population aged > 70 years old are affected by diverticular disease. But this condition is rare before 35 years old.
Incidence is more common among females.

Though the entire colon may be affected, but the commonest site is the sigmoid colon, probably after intake of low residual diet, the intramural pressure over sigmoid colon is the highest.

Pulsion of diverticulae emerged in between the mesenteric and anti-mesenteric taenia, through the circular muscles, at points where the blood vessels penetrates through it.

Hence, diverticular disease will never occur in the rectum.
This is due to it's different arrangement of blood vessel, and it's longitudinal smooth muscle covers the entire circumference of the rectum.

Sometimes, a caecal diverticula may be obstructed by a faecolith or by inflammatory processes.
Hence resulting in acute appendicitis (mimics simple acute appendicitis)

Clinical features

Colonic diverticular disease are mostly asymptommatic.
Most of the cases are detected during investigation of other GI diseases, where diverticular disease are found incidentally.

Occasionally, patient may present with intermittent lower abdominal/LIF pain and tenderness.
Other symptoms include minor rectal bleeding, defecation urgency, altered bowel habits, etc.

Barium enema shows intestinal smooth muscular hypertrophy with multiple diverticula.

Complications

1) Perforation

Purulent peritonitis
Fecal peritonitis

2) Inflammation

Pericolic abscess

 Peridiverticulitis

3) Fistula formation

Colovaginal
Colovesical
Colocolonic
Colocutaneous

4) Intestinal obstruction

Colonic fibrous fistula
Inflammatory mass, fistula
Adherent loops of small bowel

5) Bleeding

Chronic intermittent bleeding
Massive lower GI bleeding

Acute diverticulitis

1) History

Initially, patient may complains of intermittent lower abdominal pain.
Later, the pain is shifted to the left iliac fossa, which gradually becomes more constant, dull aching in nature.
If there's intestinal obstruction, the pain can be colicky in nature as well.

Often, there is lost of appetite, and nausea (rarely vomiting).
If the colonic vault is close to the bladder, it is not uncommon for the patient to have bladder symptoms (frequency, dysuria)

2) On examination

Patient appears in obvious distress, with fever and tachycardia.
Over the left iliac fossa, there is significant tenderness and guarding.
Occasionally, a tender, sausage-shaped mass may be palpable over the left iliac fossa.

Reverse Rovsing's sign is +ve : RIF is pressed, and pain is felt over LIF.
If there's intestinal obstruction or generalised peritonitis, abdomen is distended, with rebound tenderness, while on auscultation, bowel sounds is hyperactive (obstruction), or reduced (paralytic ileus - peritonitis).

Acute diverticulitis can be confirmed by Barium enema.
However, it is better to have it done 4-6 weeks later after infection has subsided.

Management

Nil by mouth
Bed rest
IV fluids
Antibiotics (Cephalosporins, Metronidazole)

If doesn't resolve, suspect pericolic abscess formation.
May requires incision and drainage of abscess, surgical resection, peritoneal toilet.