10 Essential Facts about Diverticular Disease

10 Essential Facts about Diverticular Disease

Diverticular disease is a common condition, particularly as we get older. In fact it is a normal part of the ageing process. Most people over 30 years will have some evidence of diverticular disease if they have a colonoscopy.

If this is the case, and the diverticulae are not causing symptoms it is not a disease (and the phrase in such a person is a misnomer). There is more about this issue in Point 1 below.

It involves the development of small bulges or pouches, called diverticulae, that poke through the side of the large intestine (colon). While many people have these pouches without ever knowing it, for others, they can lead to significant discomfort and medical complications.

1. There is a difference between ‘osis’ and ‘itis’

It is vital to understand the two stages of the condition:

• Diverticulosis: This is the presence of the pouches themselves. Most people with diverticulosis have no symptoms and do not require treatment.

• Diverticulitis: This occurs when one or more of these pouches become inflamed or infected, leading to severe pain and systemic illness.

2. It is often a “wear and tear” condition

Diverticula usually develop in parts of the colon that have become weakened over time. As we age, the pressure of passing hard stools through the bowel can push the inner lining through small weak spots in the muscle wall, creating the pouches. In the UK, it is estimated that 50% of people over 50 have some degree of diverticulosis.

3. Low fibre is a primary culprit

A diet low in fibre is considered the leading cause of the disease. Fibre keeps stools soft and bulky, allowing the colon to move them along easily. Without enough fibre, the colon has to work much harder and exert more pressure to move smaller, harder stools, which encourages the formation of diverticula.

4. The “Left-Sided” pain

The most common symptom of diverticular disease (and diverticulitis) is a persistent pain in the lower left side of the abdomen. This is because diverticula most commonly form in the sigmoid colon, which is located in the lower left quadrant of the tummy.

5. Diverticulitis can feel like “Left-Sided Appendicitis”

When a pouch becomes infected (diverticulitis), the pain often becomes sharp and constant. It is frequently accompanied by a high temperature (fever), nausea, and a general feeling of being very unwell. Because the symptoms are similar to appendicitis but usually on the opposite side of the body, it is sometimes nicknamed “left-sided appendicitis.”

6. It can cause significant rectal bleeding

Diverticular disease is one of the most common causes of sudden, painless, bright red blood from the rectum. This happens because a small blood vessel located within a diverticulum can burst. While often alarming, this bleeding sometimes stops on its own, though it always requires medical assessment.

7. Diagnosis is usually via CT or Colonoscopy

Diverticulosis is often found incidentally during a routine colonoscopy. However, if a doctor suspects active diverticulitis, they will usually avoid a colonoscopy in the short term due to the risk of perforating the inflamed bowel. Instead, a CT scan is the “gold standard” for seeing the inflammation and checking for complications.

8. Complications can be serious

If diverticulitis is not treated, it can lead to:

• Abscesses: Pockets of pus near the infection.

• Perforation: A small tear in the pouch that can leak waste into the abdominal cavity (peritonitis).

• Fistulas: Abnormal tunnels that form between the bowel and other organs, like the bladder.

9. Management changes depending on the stage

The advice for diverticular disease is often “contradictory” because it depends on your current health:

• During a flare (Diverticulitis): You may be told to follow a low-fibre or liquid diet to give the bowel a rest while taking antibiotics.

• To prevent flares (Diverticulosis): You should follow a high-fibre diet and drink plenty of water to keep stools moving easily.

10. Persistent bowel changes need checking

Because the symptoms of diverticular disease—such as bloating, pain, and changes in bowel habit—overlap with other conditions, it is vital not to self-diagnose. Specifically, a prolonged change in bowel habit can also be a sign of colon cancer. Both conditions are common in older adults, and only a medical professional can tell them apart.

MyHSN Top Tip: While diverticular disease is a benign (non-cancerous) condition, it can mask the symptoms of more serious issues. If you have been diagnosed with diverticular disease but notice a new or persistent change in your bowel habits, or see blood in your stool, always consult your GP to ensure a correct and up-to-date diagnosis.