Diverticulosis is the condition of having diverticula in the colon which are outpocketings of the colonic mucosa and submucosa through weaknesses of muscle layers in the colon wall. These are more common in the sigmoid colon, which is a common place for increased pressure. This is uncommon before the age of 40 and increases in incidence after that age.^[1] Diverticulosis may be asymptomatic or symptomatic.

Diverticular disease is defined as clinically significant and symptomatic diverticulosis due to diverticular bleeding, diverticulitis, segmental colitis associated with diverticula or symptomatic uncomplicated diverticular disease.

The Diverticulosis described as early as 17th century but, most of the information we now have is based on much of the work during the 20th century^[2].

Diverticulosis may be asymptomatic or symptomatic. Diverticular diseases categorized as their symptoms to the^[3]:

• Diverticular bleeding
• Diverticulitis
• Segmental colitis associated with diverticula
• Symptomatic uncomplicated diverticular disease

The most important scenario behind the formation of Diverticula is, weakness in colon wall. Increased motility and increased level of VIP are another factors^{[4][5][6][7][8][9]}.

It depends on the Pathologic event that causes the symptomatic disease.It may lead to Lower GI Bleeding or diverticulitis. Either of this disorders has it’s own related differential diagnosis including: ^[10][11]: Colonic Ischemia,anorectal source of bleeding(hemorrhoids, anal fissures, rectal ulcers),neoplasia (polyps and cancers),Angiodysplasia,Postpolypectomy,Inflammatory bowel disease,Other colitis (infectious, antibiotic associated, colitis of unclear etiology),Small bowel/upper GI bleed

The prevalence of diverticulosis is age-dependent, increasing from less than 20 percent at age 40 to 60 percent by age 60.^[12][13] Western and industrialized nations have prevalence rates of 5 to 45 percent, depending upon the method of diagnosis and age of the population. Approximately, 10% of the US population over the age of 40 and half over the age of 60 has diverticulosis. This disease is common in the US, Britain, Australia, Canada, and is uncommon in Asia and Africa. It is the most common cause for rectal bleeding in US adults over the age of 40 years.Approximately 95 percent of patients with diverticula have sigmoid diverticula.

Risk factors for diverticulosis include low intake of dietary fiber, high intake of fat and red meat, and obesity^[14][15][16].

There is insufficient evidence to recommend routine screening for diverticulosis.

Majority of patients with diverticula remain asymptomatic^[17],it may progress to symptomatic disease based on the pathologic events that includes:Acute diverticulitis and Lower GI Bleeding Overall prognosis of Diverticulosis is excellent. Once the symptomatic disease occurs mortality rates vary depending on the presence of complications and patient comorbidities^[18]. In patients with acute uncomplicated diverticulitis, conservative treatment is successful in 70 to 100 percent of patients and mortality is negligible^[18].

The most common symptoms including^[19]:Bleeding (variable amounts), Bloating, Abdominal pain/cramping after meals or otherwise often in the left lower abdomen, changes in bowel movements (diarrhea or constipation).

Diverticulosis will not cause any physical findings unless progress to symptomatic disease such as: Diverticulitis or Lower gastrointestinal bleeding.

On contrast imaging of the gastrointestinal tract (e.g, computed tomography [CT]/magnetic resonance [MR] enterography), bowel diverticula appear as globular outpouchings^[20].

Diverticula may be visualized as outpouchings of the wall that have the appearance of a blind sac^[21].

Often no treatment is needed unless the symptomatic disease develops. If the patient develops the symptomatic disease(Lower GI Bleeding, Diverticulitis) one of medical therapy or surgical therapy based on the condition will be consider.

Dietary fiber and a vegetarian diet may reduce the incidence of symptomatic diverticular disease by decreasing intestinal inflammation and altering the intestinal microbiota.^[15]. vigorous physical activity appears to reduce the risk of diverticulitis and diverticular bleeding.^[22].