Diverticular disease is usually a nutritional disease of the Western world. It has to do with the low fiber content of our food.
Due to increased pressure inside the large bowel (caused by slow transit of the bowel contents) small “blisters” form in the bowel wall (diverticula). This happens mostly in the lower left portion of the large bowel (sigmoid). The thickness of the wall in a diverticulum is only a 1/10th of the normal healthy bowel wall and therefore it is no surprise that bacteria from the bowel manage to escape through this thinned out part of the bowel wall. This again leads to inflammation within and around the bowel wall. see figure
Worst case is a complete perforation of the bowel wall with leakage of stool into the abdominal cavity with severe, life threatening peritonitis. Inflammatory swelling of the bowel wall causes narrowing of the bowel (stenosis) and problems with passage of stool occur (from mild constipation to complete bowel obstruction).
This explains the typical symptoms and signs: Pain (sometimes colicky, often continuous) in the left lower abdomen, distension, constipation, fever etc. Laboratory tests show an increase in Leucocytes (white blood cells) and a raised CRP (another very important inflammatory parameter).
Diagnosis is confirmed by clinical examination, sonography and most of all by CT scan with contrast medium applied as an enema. The role of colonoscopy in the diagnosis of diverticulitis is discussed controversial. Personally I do not use colonoscopy in acute diverticulitis; in fact I believe I can actually be dangerous for the patient.
Diverticular disease is initially treated conservatively. The bowel is put to rest. The patient receives iv-fluids and strong antibiotics. Quite often this necessitates hospitalization of the patient, in order to be able to intervene surgically without delay, if necessary.
An operation becomes necessary, when conservative treatment fails to improve the symptoms or if symptoms deteriorate, if the inflammatory attacks (diverticulitis) recur or when severe complications like perforation, stenosis, fistula formation (inflammatory connections form between bowel and adjacent organs like bladder, small bowel or vagina) or abscesses in the abdomen or liver occur. Patients below the age of 50, patients with HIV or other forms of immune suppression (transplant patients, patients on corticosteroids etc.) have an increased risk for severe complications and should be elected for surgery after the first severe attack of diverticulitis.
The aim of surgery is to remove the inflamed segment of the sigmoid colon. (about 30 cm). The ends of the bowel are reconnected by suture or staples (anastomosis). This procedure is almost always possible without a diverting stoma today. The basis for this very safe procedure is the concept of “early elective surgery”. We try to avoid operations in the very acute phase, treat the patient conservatively for a few days (3-5 days) and when everything has cooled down a bit we operate.
In many cases this operation can be done laparoscopically (minimal invasive) or laparoscopically supported. This carries many advantages for the patients and I favor this approach. In some cases the situation and the circumstances call for a conventional open procedure.
An (early) elective procedure takes 60-90 minutes. Hospital stay has decreased significantly in the last 10 years thanks to modern operative techniques and “fast track” postoperative management and is between 4-8 days.