Diverticulitis is a disease of the digestive system, and is the result of diverticula inflammation. Diverticula are small sacs that develop at weak points in the lining of the large intestine (colon).
Symptoms of diverticulitis are usually constant and severe. These include:
- Agonising lower abdomen pain
- Episodes of diarrhoea and constipation
The cause of diverticulitis is not currently known. Risk factors include non-steroidal anti-inflammatory drugs (NSAIDs), a low fibre intake, obesity, smoking and genetic factors. It is thought to be 40 per cent attributable to inherited factors, and 60 per cent due to environmental factors. 
Although the exact mechanism has not yet been proved, the NHS has asserted that the hard, small, and occasionally sharp stool that is associated with a lack of dietary fibre, coupled with the high pressure it takes to move the stool through the large intestine, damages the muscular outer layer. This then allows the inner layer to protrude in, causing diverticula.
Serious cases of diverticulitis require hospitalisation and should not be self-medicated. Mild cases, however, can be treated at home. Antibiotics and pain medication will be prescribed but it is also important to follow a liquid diet in order to give the large intestines time to heal.
The liquid diet is a temporary diet that puts minimal stress on the large intestines. For the first two days, drink only clear liquids such as water, tea, broth, jelly and squash.
After two days, a full liquid diet can be consumed. This includes: diluted fruit and vegetable juices that contain no pulp (as they contain essential vitamins and dietary elements), very thin creamed soup and broth (that contain no solid pieces), jelly, ice lollies and importantly, protein shakes, to ensure you don’t become too weak. These can be made with water, and occasionally with semi-skimmed milk.
Once you have the go-ahead from your doctor, it is time to slowly introduce solid foods. This needs to be a gradual process, as it can aggravate symptoms if done incorrectly. Starting with low-fibre foods is advised, which includes meat, poultry, fish, dairy, eggs and white bread.