Diverticulosis is a condition in the colon (large intestine) that causes small sacs to form, leading off from the main part of the colon. If these sacs become inflamed or irritated, this condition is called diverticulitis. Diverticulitis is more common in older adults and occurs most often in the sigmoid, or lower, portion of the colon that leads to the rectum.
What causes the sacs, or diverticula, to form in the first place could be compression on the weaker areas of the colon wall, which may happen as you get older. These weaker areas then protrude outward, causing the sac to form.
Diverticulitis is thought to be caused by one of three things: even more compression on the diverticula, causing the area to decompose, which then could get infected; faeces getting trapped in the little sacs, which leads to much irritation and sometimes causes them to get infected; something getting stuck back in the recesses of the diverticula, cutting them off from blood flow, which could then lead to irritation of the area.
The older you get, the more susceptible you may be to diverticulitis, due to the wall of the colon growing weaker in certain spots. Also, if you are not consuming enough fibre in your diet, you are even more at risk, as fibre helps things to move through the colon more smoothly, without all the pressure. If you are not very fit, and you do not get up and exercise, this could also be a risk factor. Exercise increases motility in the colon and helps things to stay moving along.
If you have diverticulitis, you will usually have a lot of pain in the area of the abdomen where the diverticula are located, usually more so in the left side. If the diverticula become infected, you may even develop a fever. You may alternate between becoming constipated and not being able to make it to the bathroom in time with diarrhoea. You also will have quite a bit of gas and may have blood loss from your rectum. If your diverticulitis causes a lot of pain, you may experience an upset stomach as well.
If you develop an infection, your white blood cell count will increase in your blood work. If the doctor feels around the abdomen, he may be able to feel a swelling in it. A CAT scan may be done to check the location and severity of the diverticula. If you are not highly symptomatic, the doctor may order a barium enema or colonoscopy so that he can actually see the diverticula.
If the diverticula do become infected, an abscess can start. This abscess can, in turn, burst and leak intestinal contents into the abdomen, a condition that needs to be treated immediately. It may also even tunnel over to another organ, causing a fistula, which is a tunnel or channel that leads from one organ to another. Also, the colon may become obstructed, causing the need for surgery to remove the obstruction. If bleeding from the rectum is severe, you may become anaemic.