Prof. Dr. med. Robert Rosenberg, FACS, EMBA, is a recognized specialist in the field of general and visceral surgery as well as oncological surgery. As Chief of the Department of General and Visceral Surgery at the Baselland Cantonal Hospital in Liestal, he also heads the certified colorectal cancer center, which is one of the leading facilities of its kind in Switzerland. His clinical focus is on the treatment of tumors of the gastrointestinal tract, particularly colon and rectal cancer, as well as benign conditions of the colon and rectum.
With his comprehensive training, which he completed both at the Klinikum rechts der Isar in Munich and at renowned hospitals in the United States, Prof. Dr. Rosenberg possesses in-depth international surgical expertise. His particular areas of expertise include minimally invasive surgery, robot-assisted surgery using the Da Vinci system, laparoscopic surgery, and traditional open surgery. All procedures are individually tailored to each patient’s specific situation and are based on current national and international guidelines.
In tumor surgery, Prof. Dr. Rosenberg aims to ensure oncological safety through precise surgical techniques while simultaneously preserving patients’ quality of life. Prof. Dr. Rosenberg combines surgical precision with empathetic patient care, and through his dedication, he plays a key role in maintaining the highest standards of visceral surgical care in the Basel region and beyond.
In an interview with Prof. Dr. Rosenberg, the editorial team of the Leading Medicine Guide learned more about the treatment of diverticulitis.
Diverticulitis is an inflammatory condition of the large intestine in which small pouches in the intestinal wall—known as diverticula—become inflamed. These changes occur particularly frequently in the sigmoid colon, the lower part of the large intestine, and are widespread in Western industrialized nations. While many people have diverticula without experiencing any symptoms, diverticulitis can suddenly cause severe abdominal pain, fever, and changes in bowel function. The development of the disease is influenced by various factors, such as a low-fiber diet, age, or a genetic predisposition. In most cases, diverticulitis can be treated conservatively; however, surgical intervention may be necessary in cases of recurrent or complicated disease.
The development of diverticula in the large intestine is influenced by a variety of factors, with mechanical, dietary, and age-related aspects playing a significant role.
“Diverticula occur particularly frequently in the so-called sigmoid colon, a section of the large intestine located about 20 to 30 centimeters before the rectum. In the Western world, this is the region where diverticula are most common and where inflammation is most likely to occur. Whether and how diverticula develop depends on various factors. Some of these can be influenced, while others cannot. One of the most important uncontrollable factors is age: As people age, the elasticity and strength of the intestinal wall decrease, making it easier for diverticula to form. It is estimated that about 50 to 60 percent of people over the age of 70 have diverticula. However, diverticula are also becoming increasingly common among younger people today. Another uncontrollable risk factor is genetic predisposition. Many patients report that their parents or grandparents were already affected—this familial link has also been scientifically proven. “A hereditary component therefore appears to play a role in their development,” explains Prof. Dr. Rosenberg, who goes on to describe factors that individuals can control themselves:
“In addition, however, there are modifiable lifestyle factors that can promote the formation of diverticula. These include, in particular, a diet low in fiber. People who consume little fiber are more prone to constipation. This makes stools harder, slows their passage through the intestine, and increases pressure on the intestinal wall. This can not only promote the development of diverticula but also increase the risk of inflammation if fecal matter accumulates in the pouches. A sedentary lifestyle, being overweight, high consumption of red meat, and regular alcohol consumption are additional factors that can increase the likelihood of diverticula and their complications. These associations are also considered a possible explanation for why more and more younger people are affected today. As for the widespread belief that people with diverticula should avoid tomato seeds, chili seeds, or nuts, this cannot be confirmed based on current evidence. Although such recommendations were made in the past, current data and medical guidelines do not identify a proven link. These foods are now considered safe for people with diverticula. It is also important to know that many people have diverticula without ever developing symptoms. Only about 5 to 10 percent of those affected will develop diverticulitis at some point in their lives. So-called diverticulosis—that is, the mere presence of diverticula—is therefore not a clinical condition. Symptoms usually do not appear until the diverticula become inflamed.”
Uncomplicated and complicated cases of diverticulitis differ fundamentally in their clinical presentation, the diagnostic tests required, and the resulting treatment approaches.
In uncomplicated diverticulitis, only the diverticula themselves are inflamed, without any serious complications such as abscess formation, perforation, fistula formation, or intestinal strictures. Typical symptoms of uncomplicated diverticulitis include localized pain, usually in the left lower abdomen, mild fever, changes in bowel habits, and a general feeling of illness. Diagnosis is often based on a combination of medical history, physical examination, and imaging techniques such as ultrasound or computed tomography (CT), with contrast-enhanced CT considered the gold standard for reliably assessing the inflammatory activity and extent of the disease.
“In cases of acute, uncomplicated diverticulitis, surgery is generally not necessary—it is treated conservatively. While people are quick to turn to antibiotics, there is now a solid body of evidence showing that such a flare-up can be treated without antibiotics. Provided, of course, that the patient has a stable home environment, can drink enough fluids and eat a little food despite the inflammation, and ideally has a primary care physician who can closely monitor the situation over the next few days. In that case, outpatient treatment is certainly a viable option. In practice, however, antibiotics are still often prescribed, simply because the inflammation is sometimes perceived as being somewhat more severe—that is certainly still the reality. Presumably, this results in far too many antibiotics being used overall, even though in many cases they aren’t necessary. The important thing to remember is: If symptoms improve with this conservative treatment, there’s no reason for surgery. Surgery would only be considered if the inflammation doesn’t subside with treatment—in other words, if the flare-up doesn’t go away. Then it would be necessary to consider it. “Outpatient” in this case means plenty of rest, adequate fluid intake, pain medication, and taking it easy. Stress likely plays a role as well—so it’s important to give your mind a break, too. In most cases, the symptoms then improve quickly,” says Prof. Dr. Rosenberg.
With increasing age, the prevalence of diverticula in the large intestine increases significantly, which is attributable, among other things, to age-related changes in the structure of the intestinal wall and reduced connective tissue stability. Older patients also more frequently exhibit atypical or less pronounced symptoms, which can make diagnosis more difficult and increase the risk of a complicated course of the disease.
In complicated cases, more severe clinical presentations occur, which may include life-threatening complications such as perforations with free air in the abdominal cavity, extensive abscesses, fistulas to other organs, or intestinal strictures. In these cases, symptoms are often significantly more pronounced, with more severe pain, high fever, a septic clinical picture, or acute abdominal rigidity in cases of perforation. Diagnosis must be more comprehensive in these situations, as a rapid assessment of complications is necessary to make the correct therapeutic decision. In addition to CT scans, targeted abscess drainage under image guidance and endoscopic procedures may be used for follow-up monitoring; however, a primary colonoscopy is avoided during the acute phase to prevent an increased risk of perforation.
If surgery for diverticulitis becomes unavoidable—for example, because the inflammation does not subside or a bowel perforation occurs—the question naturally arises as to how the procedure is actually performed and which methods are used.
“Whenever possible, surgeons try to operate during a period when there is no inflammation. The chances of recovery are significantly better in this case, and the risk of complications is low. However, if surgery must be performed while the bowel is still inflamed—for example, in an acute emergency situation—a minimally invasive approach is still used in most cases today—that is, the so-called keyhole technique. This can be performed either laparoscopically or, if available, with the assistance of a surgical robot. The goal of the procedure is to remove the inflamed section of the intestine—typically about 20 centimeters of the colon. Ideally, the two healthy ends of the intestine are reconnected immediately. Only in specific emergency situations, when the inflammation is too severe, may it be necessary to temporarily create a colostomy to give the body time to recover. However, this is not necessary in elective surgeries. For many patients, the mere thought of surgery—or even a colostomy—is a source of great anxiety. That is why it is particularly important to carefully weigh the decision. In cases of chronic, recurrent diverticulitis—that is, when inflammatory flare-ups occur repeatedly—patients should discuss the benefits and risks of surgery in detail with their doctor. Although complications can never be completely ruled out, the risk of inadequate healing of the intestinal anastomosis is only two to three percent in the hands of an experienced surgeon and is therefore comparatively low. The major advantage of surgery is that removing the source of inflammation usually results in lasting improvement. Patients then generally no longer need to undergo repeated courses of antibiotic therapy and experience a noticeable improvement in their quality of life. This predictability is a decisive factor, especially for people who travel frequently or have demanding jobs. Studies now also clearly show that quality of life after a well-performed surgery is, in many cases, significantly higher than with recurring conservative treatments. There is a low residual risk of diverticulitis recurring after surgery. This is because the entire colon is not removed; instead, the specific section where the susceptibility to inflammation is particularly high is targeted—typically about 20 to 30 centimeters before the rectum, where pressure in the intestine is greatest. This is usually sufficient to resolve the symptoms in the long term. “In very rare cases, however, diverticula in other parts of the intestine may cause problems again,” explains Prof. Dr. Rosenberg.
After a successful surgery and discharge from the hospital, one thing is of primary importance to patients: What can I do myself to prevent relapses and support my gut health in the long term?
Prof. Dr. Rosenberg recommends: “The guidelines that apply after surgery are similar in many ways to those that were already important before the onset of the disease—but they now take on even greater significance. A key factor is diet. A high-fiber diet is crucial for keeping stools soft and supporting the bowel’s natural movement. Specifically, this means regularly incorporating fruits, vegetables, whole grains, legumes, and nuts into your diet. The goal is to reduce pressure in the intestines, as excessive pressure plays a key role in the development of diverticula and inflammation. To ensure that the fiber can work effectively, adequate fluid intake is important—at least 1.5 liters of water per day is recommended. This is the only way to keep stools soft and ensure they can be passed easily. Consciously managing certain risk factors is also part of follow-up care. Consumption of red meat and highly processed foods should be reduced, as links between these foods and inflammatory processes in the gut are being discussed. A balanced, plant-based diet can help minimize this influence. Physical activity is equally important. Regular exercise promotes bowel function and supports a healthy body weight—a factor that should not be underestimated, as being overweight increases the risk of recurrence. In addition, there are aspects that are often underestimated: stress management is one such factor. Chronic stress can have a negative impact on the immune system and inflammatory processes in the body—including in the gut. That’s why it can be helpful to actively seek relaxation, whether through meditation, yoga, mindfulness, or other personal stress-management techniques. Taking time to unwind regularly benefits not only your mind but also your digestive system. Finally, quitting smoking is also an important part of aftercare. Smoking can impair blood flow to the intestines and is also suspected of promoting inflammatory processes. So anyone who wants to actively support their own healing will find in all these measures an effective way to contribute to their long-term gut health.”
According to current scientific knowledge, there is no direct link between diverticulitis and colorectal cancer—diverticula or inflammatory flare-ups do not themselves lead to cancer.
“But it’s important to remain vigilant after recovering from diverticulitis. This is because clinical observations show that people with a history of diverticulitis develop colorectal cancer slightly more frequently than the general population. This suggests that there may be common risk factors—such as diet, environment, or lifestyle—that can promote both inflammation and malignant changes in the colon. That is why we routinely recommend a colonoscopy after a bout of diverticulitis has resolved, about four to six weeks after the acute symptoms have subsided. This allows polyps or other abnormalities to be detected early and, if necessary, removed. However, if symptoms are not taken seriously or remain untreated for an extended period, the inflammation can become chronic and lead to complications. These include, for example, the formation of fistulas—abnormal connections between the intestine and neighboring organs, such as the bladder. The formation of an abscess—a localized collection of pus—is also possible. This often occurs when the inflamed section of the intestine partially ruptures, but the body is able to contain the situation locally. Such complicated cases always require inpatient treatment with antibiotics. If the abscess is larger, it is punctured and drained under image guidance, usually under CT guidance. Subsequently, a decision regarding a possible surgery can be made jointly—not during the acute phase, but as a planned procedure with a clear focus on safety and healing,” explains Prof. Dr. Rosenberg.
Diverticulitis is one of the most common abdominal conditions for which patients present to the emergency department.
“At our hospital, we see people almost every day who present with the typical symptoms—that is, pain in the lower left abdomen, fever, or digestive problems. In many cases, a decision can be made quickly after the initial diagnosis as to whether hospitalization is necessary or whether the patient can continue to be cared for on an outpatient basis, that is, at home. This assessment is made on a case-by-case basis—depending on the severity of the inflammation, the patient’s general condition, and available care options. As a hospital specializing in colorectal surgery, we not only treat acute flare-ups conservatively but also regularly perform surgeries when necessary—whether due to recurrent inflammation or because an acute situation requires a surgical solution. “We perform several such procedures each week, which underscores just how widespread and clinically relevant this disease is,” Prof. Dr. Rosenberg emphasizes at the conclusion of our conversation.
Thank you very much, Professor Dr. Rosenberg, for this important information!
