What is diverticular disease?
Diverticular disease, sometimes called diverticulosis, refers to the presence of small sacks, or pockets, in the colon that balloon out of the bowel ball and can create a webbing inside the colon. It occurs most commonly on the lower lefthand side of your colon which is next to your pelvis.
As you can see from the picture (right), it is easy for waste to get stuck in the pockets as it moves through your colon. This is what can cause pain. When waste gets trapped for longer periods, it can cause infection and active diverticulitis, which leads to pain, fever, and often blood in the stool.
We used to believe that diverticular disease was caused by a poor diet and lifestyle but now we understand that some people are genetically more prone to it and that it is likely to be linked to other connective tissue problems. It is important to remember that if you have diverticular disease, it isn’t your fault and that although we can’t cure it, we can make the symptoms much better and reduce the likelihood of flares through diet.
Why does diverticular disease cause bloating, pain and diarrhoea?
Diverticular disease causes bloating usually due to increased sensitivity to some foods that can ferment in the colon, such as onion, garlic and apples. Whenever the colon is unsettled, it can lead to more bloating. The colon is 1.5 metres long, so anytime it is filled with gas or stool, it is going to cause the stomach to appear more bloated.
Diverticular disease causes pain because the bowel is more sensitive to being stretched by stool or gas and because the stool is being dragged through the pockets and the structural changes as it moves through. Pain may also indicate that there is inflammation in the bowel or active diverticulitis.
Diverticular disease causes diarrhoea for a few reasons, but the urgent diarrhoea that is the most debilitating is usually caused by the changes to the structure of the bowel causing the colon to have to force the stool through more rapidly. It may also be caused by fermentable foods.
People who have had antibiotics for their diverticular disease are more likely to develop functional gut symptoms such as Irritable Bowel Syndrome (IBS) alongside their diverticular disease. This may account for many of the symptoms that people experience. The good news is that there is dietary treatment for IBS, which is effective for 80% of people.
What foods trigger diverticular disease?
There is a lot of conflicting information about diet and diverticular disease because we haven’t done enough good quality studies to say what the best way to manage it is. That said, with over 10 years of experience as a colorectal dietitian, CityDietitians has a lot of experience managing it.
The first thing to remember is that some things are more likely to get trapped in the pockets in the bowel than others. Foods containing skins, peels and pips are the biggest culprits for this. That means that seeded bread, peas, sweetcorn, pulses and mushrooms are less favourable. These all contain insoluble fibre which adds bulk to the stool, often contributing to pain.
That doesn’t mean to say that cutting out all healthy foods and sticking to a beige diet is a good idea in any way. We still need to make sure that people living with diverticular disease are getting plenty of fresh fruits and vegetables and a type of fibre called soluble fibre, which keeps the stool soft and easy to pass, reducing the chances of more pockets developing in the bowel.
Focus on fruit like melon, papaya, peeled fruits and bananas, and root vegetables like carrots, beetroot, parsnips, butternut squash and pumpkin. Try to make vegetable soups to keep your veggie intake high, choose brown bread without seeds, and have pulses in the form of hummus or dhal.
The ideal diverticular disease diet
The optimal diet for diverticular disease is the same as the rest of the population with a few small changes.