A diverticulum is a small pouch in the wall of the gut (intestine). ‘Diverticula’ means more than one diverticulum. They can develop on any part of the gut but usually occur in the colon. They most commonly develop in the section of the colon leading towards the back passage (rectum), where stools become more solid. Several diverticula may develop over time.

Diverticula are common. They become more common with increasing age. About half of all people in the UK have diverticula by the time they are 50 years old. Nearly 7 in 10 have diverticula by the time they are 80 years old.

Diverticula (diverticulosis)

The reason why diverticula develop is often due to a lack of dietary fibre. Fibre is the part of food that is not digested.

Your intestine moves faeces with gentle squeezes of its muscular wall known as peristalsis. A lack of fibre and water encourages drier, smaller, and more difficult to move faecal matter. Your gut muscles have to work harder if there is too little fibre in your gut. High pressure may develop in parts of your gut when it squeezes hard stools. The increased pressure may push the inner lining of a small area of your gut through the muscle wall to form a small diverticulum.

Diverticular disease

This term is used when diverticula cause intermittent, lower tummy (abdominal) pain or bloating (without swelling inflammation or infection) The pain can be crampy and may come and go. You may get ease from pain and bloating by going to the toilet and passing a bowel movement. Some people develop diarrhoea or constipation, and some people pass mucus with their stools.

Diverticulitis (inflamed or infection diverticula)

Diverticulitis is a condition where one or more of the diverticula become inflamed/infected. This may occur if some faeces get trapped and stagnate in a diverticulum. Germs (bacteria) in the trapped faeces may then multiply and cause infection. 

Causative factors

The most common theory associated with diverticula development is a low fibre diet. Lack of fibre can lead to constipation which in turn puts pressure on the walls of the colon. This increased pressure causes tiny pockets of gut lining injury known as diverticula.

Diverticulitis develops due to faecal matter and bacteria becoming trapped in diverticula encouraging inflammation and further injury to the mucosal barrier/ gut wall.  


Patients with diverticula (diverticulosis) may have no symptoms or complications.

Patients whom develop diverticula disease or diverticulitis may experience

  • Abdominal discomfort usually in your lower left side. Pain may be intermittent and perhaps worse during or shortly after eating. Passing a bowel movement may bring short term relief.
  • Constipation and or diarrhoea
  • Occasional blood in stool

If diverticula become infected and inflamed (diverticulitis) symptoms may include:

  • Increased severe abdominal pain
  • A temperature
  • Diarrhoea or constipation
  • Mucus or blood when passing a bowel movement
  • Rectal bleeding

Associated Conditions

  • IBS – irritable bowel syndrome
  • IBD – inflammatory bowel disease
  • SIBO – small intestinal bacterial overgrowth

Functional Tests

Diagnosis of Diverticula/Diverticulitis is achieved via GP or gastroenterologist.

Typically, beyond dietary fibre and constipation avoidance I have found additional drivers of this condition. My role is to identify, understand and address the development of these pouches and inflammation. Testing options include:  

Comprehensive Stool Testing

Provides invaluable information facilitating a tailored action plan. Assessment includes commensal colonic bacteria, opportunistic bacteria, yeast species, pathogens, worms, parasites, inflammation, colonic immune dysregulation, digestive impairment and Stool ph.

Small Intestinal Bacterial Overgrowth (SIBO) – breath Testing

The 3 Hour SIBO Breath Test identifies bacterial overgrowth in the small intestine. SIBO may co-exist alongside diverticula, exasperating the condition. SIBO can alter bowel activity slow transit time, encourage constipation, impair digestion and negatively influence diverse and abundant colonic microbiome.

Organic Acid Testing

First morning urine collection. Identifies metabolites associated with specific bacterial and fungi/mould overgrowth in both the small and large intestine. Identifies nutritional deficiencies and metabolic dysregulation impacting on energy production.

Considerations for intervention

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Meet Paula

Paula is a functional nutritionist with over 14 years of professional experience.

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