Diverticular disease

What is diverticular disease?

In diverticular disease, also called diverticulosis, the walls of the intestinal tract have become herniate and form sack like protrusions into the gut wall, called diverticula. Diverticula can form in any area of the gut wall between the oesophagus and colon (large intestine), however they are most commonly located in the sigmoid colon (the last section nearest to the rectum). Although diverticular disease can be for the most part uneventful, serious complications can develop, including bleeding, diverticulitis (infection of the diverticular) and the very serious condition perforated abscess, which require medical intervention.

What causes diverticular disease?

Diverticular disease is far more common in populations where people have a low dietary fibre intake. A low fibre diet can also by default reflect general Western dietary patterns. Therefore other unhealthy dietary habits such as high intake of sugar, fat, processed food and sugary soft drinks and low intake of fruit and vegetables may also contribute to the development of diverticular disease, rather than lack of fibre being the only culprit. The main mechanism involved in the development of diverticular disease is raised colonic pressure:

Colonic pressure: the food we eat, such as fibre, can influence our stool form, gut structure and gut motility (the muscular contractions which move food along the gut passage). It is thought that diets with low fibre precipitate a colon of small diameter. The small diameter, often in combination with hard poorly formed stools, requires stronger contractions and a high build up of pressure in the colon to move the faeces along. It is this repeated force on the gut wall that is thought to lead to herniation of the gut wall.

What are the symptoms of diverticular disease?

Many people with diverticular disease have no symptoms. Others experience common digestive symptoms (not specific to diverticular disease) including:
  • Change to normal bowel habits
  • Constipation
  • Bloating
  • Abdominal discomfort

How common is diverticular disease?

Diverticular disease affects around 10% of adults over 40, and rises considerably to affect around 50% of adults by their 60’s.

What diet and lifestyle strategies can prevent or support diverticular disease?

Strategies to support and prevent diverticular disease should focus on reducing high pressure in the colon, primarily by increasing transit time and regularity of bowel movements. Dietary recommendations for people with diverticular disease should also be tailored according to an individual’s full presentation of symptoms, for example constipation, bloating, wind, or if they have irritable bowel syndrome. Therefore the general guidelines listed below will not apply to everybody as some foods can aggravate digestive symptoms in sensitive individuals. Seeking personalised dietary advice from a qualified Nutritional Therapist is recommended. Dietary protocols may include:
  • Low FODMAPs diet
  • High fibre diet
  • Low fibre diet
  • Diagnostic elimination diet
  • Low sugar diet/ low GI diet
General diet and lifestyle strategies to support diverticular disease include:

Drink plenty of water throughout the day: if you are dehydrated there will be insufficient water in your bowel and stools will become hard and difficult to pass.

Eat a large variety of fruit, vegetables, nuts, beans and pulses: increasing these sources of dietary fibre can help make stools easier to pass. Fibre should be increased gradually to avoid gut symptoms.

Avoid high sugar, highly refined and processed food: sugary foods could encourage overgrowth of strains of bacteria that may contribute to gut motility dysfunction.

Eat wholegrains: increase low glycaemic index and wholegrain carbohydrates (e.g. oats, pumpernickel bread, sweet potato, brown rice). These foods are good sources of dietary fibre and promote a healthy gut flora.

Exercise regularly: exercise supports gut motility. Increase daily exercise, aiming to build up to 30 minutes per day.

Do a few relaxing activities a week: stress can be a trigger for constipation.

Flaxseeds: flaxseeds can be useful to improve bulk and form of stool. Start with 1 tablespoon of flaxseeds pre-soaked in water added to cereal or yoghurt, followed by a glass of water.

Probiotics: supplementing with certain strains of live bacteria (e.g. bifidobacterial or lactobacillus species), may support digestive health and gut motility.

Prebiotics: supplementing with fibre that encourages the growth of beneficial gut bacteria strains may also be a useful intervention to support digestive system function.

A Nutritional Therapist can help you identify diet and lifestyle factors, which may be contributing to your symptoms.