The bowel walls formed of three layers: outer serosal layer, middle muscular layer and inner mucosal layer. The middle layer is the strongest, whereas the other two layers are very thin. In healthy individuals, the muscle layer has areas of weakness where arteries and veins traverse through. If there is constant high bowel lumen pressure that stretches on the bowel wall, the mucosal layer pushes through the weakness in the muscle layer. It creates a small pocket. This pocket is called diverticulum, and it is commonly known as diverticular disease or diverticulosis. It commonly develops in the left large intestine (sigmoid colon).
Diverticular disease is a common surgical problem, affects wide range of population; it used to be a disease of elderly people. Now we come across patients in their early twenties. Poor imbalanced Diet is the main culprit. Inadequate daily water intake and diet low in fruit and vegetable are recipes for developing diverticular disease. The diverticular disease itself does NOT lead to colon cancer development.
What are symptoms or complications from diverticular disease?
Thousands of Australians are diagnosed with diverticular disease every year, and fortunately only small percentage of patients develops symptoms or complications.
The commonest complication is local infection, and it is also known as diverticulitis. It is caused by stool or food residue impacting within the diverticulum. Diverticulitis usually presents with a combination of gastrointestinal symptoms, such as acute abdominal pain, nausea, vomiting, sudden change of bowel habit or fever. Diverticulitis can be successfully treated with antibiotics and bowel rest. However, the severe and complicated infection, such as abscess (pus) formation or perforation, requires surgery or radiological intervention to prevent life-threatening peritonitis.
The second common complication is colonic bleeding. Diverticulum is less flexible and more fragile than the healthy large intestine, therefore the impaction of stool or food residue within diverticulum can injury the bowel wall and cause intestinal bleeding. The bleeding can be so profound that urgent hospitalization is required for blood transfusion and intervention
Bowel Obstruction and Fistula
Chronic recurrent infection can lead to stiffness of bowel wall and eventually blockage. This is called diverticular stricture. This is a serious complication that requires laparoscopic or open surgery to remove the affected bowel and rejoin the healthy bowel back together.
Although it is uncommon, chronic recurrent infection or severe infection can also result in abnormal communication between the bowel and the other organs. This is called fistula. The commonest site of fistula is between the bladder and the bowel, and it is known as colovesical fistula. The symptoms of colovesical fistula may include lower abdominal pain, recurrent bladder infection, and passage of urine mixed with stool or gas. The fistula needs to be repaired or removed by the surgeon.
When do I need to have colonoscopy for diverticular disease?
If you have had symptoms or a complication from diverticular disease, you will be recommended to have a colonoscopy to confirm the diagnosis and to avoid missing other important diseases, such as colonic cancer. If you had a colonoscopy within the last 2 years, it is recommended to review your symptoms and available investigations with a surgeon before proceeding to a repeat colonoscopy.
How do I prevent symptoms or complications of the diverticular disease?
Once diverticulum develops, the bowel will not return to the normal shape. However, maintaining good bowel hygiene is paramount to prevent further diverticular disease and complication. Exercising regularly, avoiding stress, and eating balanced nutrition are critical to speed up the bowel movement and soften the stool.
The Australian National Health and Medical Research Council (NHMRC) recommends that the daily fiber consumption shall be 30 grams for an adult male and 25 grams for an adult female. Adding large quantity of fiber into your diet within a short timeframe can have unpleasant side effects, such as excessive gas, fullness, or bloating. Therefore, it is wise to increase fiber consumption gradually by adding 5 grams per week. For those who cannot consume sufficient fiber from food, there are commercial fiber supplements available on the marker, such as Metamucil or Benefiber. Finally, cooking vegetables or fruits softens the textures and makes the food easier to chew, and the cooking process itself does not significantly alter total food fiber content. However, peeling the skins from fruits and vegetables can certainly cut down the amount of fiber per serving. Avoiding fruit seed or nut reduces the daily fiber intake WITHOUT reducing the chance of developing diverticulitis.
Examples of Fiber Content in Various Food (Sources from United States Department of Agriculture)
In order to supplement the effect of fiber, it is also important to ensure sufficient daily fluid intake such as water, milk, juice, and other drinks. The NHMRC recommends that the daily fluid intake is 2.6 litres of fluid a day (ten cups) for an healthy adult male and 2.1 litres (eight cups) for an healthy adult female. If you have a medical condition restricting your daily fluid intake, such as heart failure or kidney disease, you shall consult your GP or specialist first.
Physical activities stimulate the bowel movement and reduces constipation. In a healthy individual, it is recommended to conduct at least two and half hours a week of moderate intensity physical activities such as brisk walking or cycling. If you have underlying medical conditions, you shall consult your GP or specialist before doing so.