Q: What is diverticular disease?

Diverticular disease develops with age in many people, especially in western populations eating traditional western food and not much roughage. It develops in some people with age even when their intake of fiber has been high all their life. Initially the muscle wall of the colon becomes thickened (the primary event). This causes an increase in the pressure inside the colon. The colon becomes less distensible (even narrowed) and this causes the diverticular disease symptoms such as abdominal pain and the change in bowel habits. The increased pressure eventually forces the bowel mucosal lining out through points of weakness in the colonic wall (usually at points where blood vessels enters the colonic wall). The herniated lining of the bowel wall forms little pockets on the outer surface, called diverticulae (single: diverticulum) and this is the secondary event in diverticular disease, but it is the cause of most complications (such as diverticulitis, perforation etc.)

 

 

Q: What are the varieties of diverticular disease? How does diverticular disease present?

Diverticular disease can present with A) symptoms or B) complications. Distinction is essential as the management is often radically different. Symptoms are treated conservatively Except when severe, while complications frequently need surgery.

Diverticular disease symptoms: Most patients with diverticular disease (discovered during the course of investigations or surgery for unrelated causes) are probably asymptomatic. Most of those with symptoms have abdominal pain, discomfort, bloating or change in bowel habits (loose motions or constipation). There is no magic single drug that treats diverticular disease symptoms. These symptoms often respond to a combination of dietary advice and medications. What is important for patients to understand is that one has to treat the predominant symptom or symptoms prevailing at the time of consultation.

Complications:

Diverticular colitis: this is incompletely understood variety that has been recognized recently. It occurs when the mucosal aspect of the sigmoid becomes inflammed and usually result in patients complaining characteristically of a triad of symptoms; low grade discomfort or pain in the left side or the middle of the lower part of the abdomen, loose bowel motions and mucus discharge (passing slime). Not infrequently, patients may also complain of passing blood in their motions (almost always blood & mucus).

Diverticulitis: This occurs when the diverticulae (one or more) becomes inflammed (usually as a result of blockage of the mouth of the diverticulum leading into the colon). The effect is dramatic and is similar to the symptoms and signs of appendicitis (but occurs on the other side - left), with severe pain accompanied by fever. This may respond to outpatient oral antibiotics, but may also require hospital admission with intravenous antibiotics. Recurrent diverticulitis need surgery to avoid more serious complications.

Diverticular abscesses & peritonitis: On occasion an inflammed diverticulum would progress to abscess formation. This may occur on one side or the other of the colon or in the pelvis. If this is not treated early (either by an operation or drainage under radiological imaging) then it would eventually burst into the abdominal cavity causing peritonitis. This needs emergency operation.

Faecal peritonitis: sometimes an inflammed diverticulum may perforate directly into the abdominal cavity (without an intervening abscess formation) leading to Faecal peritonitis which is very serious and needs emergency operation.

Diverticular fistulae: this occurs if an inflammed diverticulum bursts into a neighboring organ, creating an abnormal communication. The commonest are colovesical fistula (If it burst into the bladder), colovaginal fistula (into the vagina) and colocutaneous fistula (to the skin). These all require operations to treat.

Diverticular stricture (narrowing): Occasionally the bowel lumen will become very narrowed causing severe difficulties with opening bowels and may progress to cause bowel obstruction. This usually need surgery

Diverticular bleeding: This is infrequent, but on occasion can be massive leading to substantial blood loss and fainting which would mandate hospital admission & blood transfusion. It may also require an emergency operation.

Severe symptoms: Sometimes, symptoms may persist and cause great deal of suffering for patients. Some patients will report that they have no quality of life because of the intensity of their symptoms. This is normally related to pain, but also can be related to difficulty in bowel evacuation. Many patients are denied the opportunity of relief by an operation (at least for a while), because the indications for surgery is less well defined in this group and because it is not always easy to distinguish patients who may eventually respond to medical management and those who won't. At the end the surgeon has to make a judgment. This primarily has to depend on the intensity of the patients symptoms and their quality of life. It may be helped partly by the severity of the disease on colonoscopy (such as presence of narrowed lumen, fixed acute bends etc.). The latter is however an imprecise measure. Some patients with severe disease on barium enema or colonoscopy have only mild symptoms. On the other hand some patients with moderate disease on barium enema or colonoscopy can be found during surgery to have a colon badly stuck in the pelvis which explain their severe symptoms. It is a matter of judgment and really need an experienced surgeon to advise in this situation.

Q: Should patients have surgery after an attack of diverticulitis? What is the role of surgery after one episode of uncomplicated diverticulitis?

A few surgeons believe that one episode of documented diverticulitis means the patient should have an elective resection of the affected segment. The majority view, however agrees that one may safely continue with conservative long term treatment after a single episode of diverticulitis. On the other hand it is clear from the evidence in many studies that the occurrence of 2 or 3 attacks of documented diverticulitis i.e. with fever, high white blood count etc. (not just recurrent diverticular pains) is really an indication for surgery. These patients not infrequently will develop more severe complications and will still require surgery, sometimes as an emergency, sometimes under imperfect conditions in a remote location. This is also more important in patients who travel and who have certain symptoms (such as those who had hysterectomy and have discomfort in their vaginas when their diverticulitis flare up - such symptoms can precede the occurrence of a colovaginal fistula).

Q: Is there a role for surgery in patients with pain from diverticular disease, but no complications?

Yes, but it is a bit more complex and the surgeon has to make a judgment whether surgery is advisable (see under severe symptoms above)

Q: Is there any relationship to cancer?

No, However, it is important to realize that the symptoms are similar and the only way to be sure of the cause of symptoms is by arranging investigations, such as colonoscopy or a barium enema. While diverticular disease does not increase the incidence of cancer, both diseases are common and they may co-exist. Likewise, having diverticular disease does not confer any protection from cancer. The main problem arise because patients may have had the symptoms for a while and they may mistake new symptoms (caused by cancer) for renewed diverticular disease symptoms. This is particularly true when patients have had investigations in the past such as barium enemas. This gives them a sense of security. It is fair to say that any total colonic examination such as colonoscopy or barium enema is probably good enough to exclude cancer for 18-24 months, after the passage of that time the patient should have new investigations if there are renewed symptoms.

Q: When should a patient be referred to a surgeon?

In the presence of any of diverticular disease complications. After an attack of documented diverticulitis. In the presence of new symptoms.