Diverticulosis and diverticulitis

Information for patients from the Department of Colorectal Surgery

You have been diagnosed with diverticular disease. This leaflet will:

If you have any questions after reading this leaflet, please speak to your GP.

What is diverticular disease?

The colon (or large intestine) can develop small pouches. These pouches bulge outward through the colon’s muscular wall. They develop in areas where blood vessels are entering the muscular wall. This area is a weaker spot that allows these pouches to form.

Each pouch is called a diverticulum. Pouches are called diverticula. The condition of having diverticula is called diverticulosis.

Pouches (diverticulum) in the colon
Pouches (diverticulum) in the colon

When the pouches become infected or inflamed, the condition is called diverticulitis. This occurs in 10 to 25 in every 100 people with diverticulosis. Diverticulosis and diverticulitis are also known as diverticular disease.

Diverticular disease is extremely common in the developed world. Between 30% and 50% of this population will be affected during their lifetime.

What causes diverticular disease?

If your stools become small and hard instead of soft and bulky, your colon has to squeeze hard to push the stool forward. These contractions create high pressure in the muscular wall of your colon. If this continues over the years, then these pouches develop at the weak areas in the wall of your colon. This is one of the reasons why diverticula are more likely to develop in the left side of the colon.

There is no exact cause of diverticular disease. However, the following could increase your risk of developing the disease:

Fibre is the part of fruits, vegetables, and grains that the body cannot digest. Some fibre dissolves easily in water (soluble fibre). It takes on a soft, jelly-like texture in the intestines. Some fibre passes almost unchanged through the intestines (insoluble fibre). Both kinds of fibre help make stools soft and easy to pass. Fibre also prevents constipation.

What are the symptoms?

Diverticulosis

Most people with diverticulosis do not have any discomfort or symptoms. However, possible symptoms may include mild cramps, bloating, and constipation. These symptoms do not always mean you have diverticulosis. Other diseases such as irritable bowel syndrome (IBS) and stomach ulcers cause similar problems. You should visit your doctor if you have these symptoms.

Diverticulitis

The most common symptom of diverticulitis is abdominal pain. The most common sign is tenderness around the left side of the lower abdomen. If infection is the cause, you may have the following symptoms as well:

How bad your symptoms are depends on the extent of the infection and complications.

What are the complications?

Diverticulitis can lead to bleeding, infections, perforations (small holes), tears, or blockages. These complications need treatment to stop them getting worse and causing serious illness.

How does your doctor diagnose diverticular disease?

To diagnose diverticular disease, your doctor will:

As most people do not have symptoms. Diverticulosis is often found through tests ordered for another condition.

Your doctor will order further tests which may include the following.

What is the treatment for diverticula disease?

A high-fibre diet and occasionally, mild painkillers will help relieve symptoms in most cases. Sometimes an attack of diverticulitis is serious enough to need a hospital stay and surgery.

Diverticulosis

Increasing the amount of fibre in your diet may reduce symptoms of diverticulosis. It may also prevent complications, such as diverticulitis. Fibre keeps stools soft and lowers pressure inside the colon. This allows bowel content to move through easily. You should eat / drink 20 to 35 grams of fibre daily. The table below shows the amount of fibre in some foods that you can add to your diet.

Your doctor may also recommend taking a fibre product such as Fybogel once a day. These products are mixed with water. They provide about 2 to 3.5 grams per tablespoon, mixed with 8 ounces of water. Fybogel and Psyllium seed products are available in pharmacies.

Until recently, many doctors suggested avoiding foods with small seeds. They believed that the seeds could lodge in the diverticula and cause inflammation. It is now generally accepted that only foods that may irritate or get caught in the diverticula cause problems. Avoid the following foods:

The seeds in tomatoes, courgettes, cucumbers, strawberries, and raspberries, as well as poppy seeds, are considered harmless. People differ in the amounts and types of foods they can eat. Make decisions about your diet on what works best for you. Keeping a diary may help identify individual items in your diet.

If cramps, bloating, and constipation are problems, your doctor may prescribe a short course of pain medication. However, many medications can cause constipation.

You should take regular exercise, lose weight if you are overweight or obese, and stop smoking. Studies do not show that these changes will definitely help all patients. But changes to a person’s lifestyle will bring benefits to general health and wellbeing.

Amount of fibre in some foods

Breakfast cereals Typical portion (weight) Fibre / portion
All-Bran 1 medium sized bowl (40g) 9.8 grams
Shredded Wheat 2 pieces (44g) 4.3 grams
Bran Flakes 1 medium sized bowl (30g) 3.9 grams
Weetabix 2 pieces (37.5g) 3.6 grams
Museli (no added sugar) 1 medium sized bowl (45g) 3.4 grams
Muesli (Swiss style) 1 medium sized bowl (45g) 2.9 grams
Fruit 'n' Fibre 1 medium sized bowl (40g) 2.8 grams
Porridge (milk or water) 1 medium sized bowl (250g) 2.3 grams
Cornflakes 1 medium sized bowl (30g) 0.3 grams
Bread / rice / pasta Typical portion (weight) Fibre / portion
Crispbreads (rye) 4 crispbreads (36g) 4.2 grams
Pitta bread (wholemeal) 1 piece (75g) 3.9 grams
Pasta (plain, fresh cooked) 1 medium portion (200g) 3.8 grams
Wholemeal bread 2 slices (70g) 3.5 grams
Naan bread 1 piece (160g) 3.2 grams
Brown bread 2 slices (70g) 2.5 grams
Granary bread 2 slices (70g) 2.3 grams
Brown rice (boiled) 1 medium portion (200g) 1.6 grams
White bread 2 slices (70g) 1.3 grams
White rice (boiled) 1 medium portion (200g) 0.2 grams
Vegetable Typical portion (weight) Fibre / portion
Baked beans Half a can (200g) 7.4 grams
Red kidney beans 3 tablespoons (80g) 5.4 grams
Peas (boiled) 3 heaped tablespoons (80g) 3.6 grams
French beans (boiled) 4 heaped tablespoons (80g) 3.3 grams
Brussel sprouts (boiled) 8 sprouts (80g) 2.5 grams
Potatoes (old, boiled) 1 medium size (200g) 2.4 grams
Spring greens (boiled) 4 heaped tablespoons (80g) 2.1 grams
Carrots (boiled / sliced) 3 heaped tablespoons (80g) 2.0 grams
Broccoli (boiled) 2 spears (80g) 1.8 grams
Spinach (boiled) 2 heaped tablespoons (80g) 1.7 grams
Salad vegetables Typical portion (weight) Fibre / portion
Pepper (green or red) Half (80g) 1.3 grams
Onions (raw) 1 medium (80g) 1.1 grams
Olives (in brine) 1 heaped tablespoon (30g) 0.9 grams
Tomato (raw) 1 medium / 7 cherry (80g) 0.8 grams
Lettuce (sliced) 1 bowl (80g) 0.7 grams
Fruit Typical portion (weight) Fibre / portion
Avocado pear 1 medium (145g) 4.9 grams
Pear (with skin) 1 medium (170g) 3.7 grams
Orange 1 medium (160g) 2.7 grams
Apple (with skin) 1 medium (112g) 2.0 grams
Raspberries 2 handfuls (80g) 2.0 grams
Banana 1 medium (150g) 1.7 grams
Tomato juice 1 small glass (200ml) 1.2 grams
Strawberries 7 strawberries (80g) 0.9 grams
Grapes 1 handful (80g) 0.6 grams
Orange juice 1 small glass (200ml) 0.2 grams
Dried fruit / nuts Typical portion (weight) Fibre / portion
Apricots (semi-dried) 3 whole (80g) 5.0 grams
Prunes (semi-dried) 3 whole (80g) 4.6 grams
Almonds 20 nuts (33g) 2.4 grams
Peanuts (plain) 1 tablespoon (25g) 1.6 grams
Mixed nuts 1 tablespoon (25g) 1.5 grams
Brazil nuts 10 nuts (33g) 1.4 grams
Raisins / sultanas 1 tablespoon (25g) 0.5 grams
Other foods Typical portion (weight) Fibre / portion
Quorn (pieces) 1 serving (100g) 4.8 grams
Chicken curry (takeaway) 1 portion meat / sauce (150g) 3.0 grams
Vegetable pasty 1 medium sized (150g) 3.0 grams
Bran (wheat) 1 tablespoon (7g) 2.5 grams
Potato crisps (low fat) 1 bag (35g) 2.1 grams
Pakora / bhajia (vegetable) 1 portion (50g) 1.8 grams
Pizza (cheese and tomato) 1 slice, deep pan (80g) 1.8 grams

Diverticulitis

Treatment for diverticulitis focuses on:

If treated early, an attack of diverticulitis without complications may respond to antibiotics within a few days.

To help your colon rest, your doctor may recommend bed rest and a liquid diet, along with pain relief.

When is surgery necessary?

Your doctor may advise surgery, if:

This involves your surgeon removing the affected part of your colon and joining the remaining sections. This is called colon resection. It aims to keep attacks from coming back and prevents complications.

If antibiotics do not correct an attack, you may need emergency surgery. Reasons for emergency surgery include:

Emergency surgery usually involves two operations. The first surgery will clear the infected abdominal cavity and remove part of your colon. Infection and sometimes obstruction, make it unsafe to re-join your colon during the first operation. Instead, your surgeon creates a temporary hole, or stoma, in your abdomen. They connect the end of your colon to the hole, with a procedure called colostomy. This will allow you to eat normally and have normal bowel movements. The stool goes into a bag attached to the opening in your abdomen. In the second operation, your surgeon re-joins the ends of your colon.

Further information

If you have any questions or concerns, please speak to the healthcare professional responsible for your care.