Diverticulosis and diverticulitis are digestive tract conditions with a common feature of diverticula, which is the term for small pouches in the intestine’s lining.

Diverticular disease is a general term that refers to conditions involving diverticula. Diverticulum is a general term for a small pouch or sac that develops in the intestinal tract.

Diverticula can occur anywhere in the digestive tract, though they are most common in the sigmoid colon (the part of the colon that is closest to the rectum).

Many people with diverticula in their colon may not experience symptoms. Diverticular disease occurs when diverticula lead to:

Read on to learn more about diverticulosis and diverticulitis, including their symptoms, treatments, and more.

A person placing their hands on the right side of their abdomen-2.Share on Pinterest
Getty Images

Diverticulosis is a clinical condition where multiple diverticula develop along the gastrointestinal tract. These sac-like protrusions typically form at weak points in the walls of the small or large intestines, though most appear in the sigmoid colon.

Health experts believe diverticula occur due to having a low fiber diet and higher pressure within the colon.

Diverticulosis is the eighth most common outpatient diagnosis in the United States. It becomes more common as a person ages, occurring in:

  • roughly 1 in 10 people over 40 years old
  • half of those over 60 years old
  • two-thirds of people over 80 years old

Diverticulitis occurs when one or more diverticulum pouches become inflamed.

Researchers are still investigating what causes diverticulum inflammation. However, certain factors, such as problems with the immune system or tissues in the colon, changes in the microbiome, or bacteria or stool getting caught in a diverticulum, may contribute.

The majority of individuals with diverticulosis do not experience symptoms, and the condition itself is not dangerous. People may experience intermittent constipation, and about 20% develop symptoms of pain or bleeding when complications develop.

Symptoms associated with diverticulosis can include:

Symptoms of diverticulitis depend on the severity of the condition. The most common symptoms of diverticulitis include:

People often report pain in the lower left side of the abdomen. The pain may feel constant and sharp and may radiate to the leg, back, groin, and side. Some may also experience urinary symptoms, such as an increased need to urinate.

Those with complications may present with long-term symptoms, such as:

Doctors may be able to diagnose diverticulosis based on the presence of symptoms. To confirm a diagnosis, they can use imaging tests, such as an X-ray with a barium enema or a colonoscopy. Typically, a colonoscopy is the best test to identify the source of bleeding in the stool.

The imaging test of choice for acute diverticulitis is an abdominal and pelvis CT scan. This can detect which part of the colon is affected and the presence of abscesses, strictures, or fistula.

An abdominal ultrasound can also diagnose acute diverticulitis. However, this highly depends on the operator’s skill.

Endoscopy is not ideal for diagnosing acute diverticulitis due to an increased risk of perforation.

A urine test can detect a urinary tract infection (UTI), which may indicate the presence of a fistula, where the urine becomes contaminated with stool from the colon.

A doctor may perform a colonoscopy 6–8 weeks after symptoms resolve to rule out other conditions, such as inflammatory bowel disease, colitis, or cancer.

Most bleeding associated with diverticulosis resolves by itself. Experts suggest 75% of bleeding episodes stop spontaneously and do not require treatment. However, a doctor may recommend a person increases the fiber and fluid in their diet to help reduce intestinal spasms.

Bulk-forming laxatives may help ease constipation. Psyllium and bran supplements may also help.

A person may need further intervention in cases of persistent bleeding or if they have a giant diverticulum at risk of infection and rupture. A doctor may recommend any of the following treatments to stop bleeding:

  • injection
  • coagulation (cautery, argon plasma coagulator)
  • mechanical devices (loops, clips, bands)

It is important to promptly treat diverticulitis because of the risk of developing complications, including:

  • an abscess
  • perforation of the colon
  • peritonitis
  • fistula formation

Standard outpatient treatment for diverticulitis includes:

Managing diverticulitis and its associated symptoms is the best prevention. Eating a high fiber diet with 20–35 grams (g) of fiber daily can help prevent it. Drinking at least eight glasses of water is also essential to make stool softer and easier to pass.

Diverticulosis and diverticulitis are related conditions that affect the large intestine. They both involve the presence of pouches called diverticula. While diverticulosis is often asymptomatic, infection of these pouches may lead to diverticulitis and other complications.

A high fiber diet and drinking plenty of fluids can help reduce the risk of diverticulitis and its associated symptoms. Treatment for acute diverticulitis may include antibiotics and bowel rest.