Diverticulitis and Diverticulosis: Symptoms of Diverticular Disease and Treatment When Diverticula in the Intestine Become Inflamed

Many people develop diverticula in the large intestine over the course of their lives. These pouches in the intestinal wall tend to form at weak points in the muscle wall when pressure in the intestine is chronically elevated. The condition only becomes clinically significant when these diverticula become inflamed. In diverticulitis, these pouches become inflamed due to trapped stool, which leads to irritation of the intestinal mucosa. Approximately 10 to 25 percent of patients with diverticula develop acute diverticulitis over time.

In contrast, a true diverticulum involves a protrusion of the entire intestinal wall. The video shows what the condition looks like during a colonoscopy: 

Typical symptoms of diverticulitis include sudden pain in the lower left abdomen, which is why the condition is often referred to as “left-sided appendicitis.” This pain in the lower left abdomen is frequently accompanied by fever, nausea, and vomiting. Changes in bowel movements, such as constipation or diarrhea, are also a common symptom. During an acute flare-up, patients often report a general feeling of illness and a palpable mass in the lower abdomen.

• severe abdominal pain, especially on the left side,
• digestive disturbances (constipation, diarrhea, bloating),
• tender, hardened areas, and
• fever.

The following dangerous complications may occur:

• Intestinal perforation: A tear in the intestinal wall and the escape of air and feces into the abdominal cavity. This can cause the inflammation to spread to neighboring structures.
• Intestinal obstruction caused by inflammation-induced thickening of the intestinal wall.

Symptoms often occur in episodes.

The presence of diverticula in the intestine and their pathological changes can be classified into different stages:

• Stage/Type 0 (asymptomatic diverticulosis): Diverticula are present but do not cause any symptoms
• Stage/Type 1 (acute uncomplicated diverticular disease/diverticulitis): Inflammation of the diverticula without complications; that is, the intestinal wall is not perforated (torn)
• Stage/Type 2 (acute complicated diverticular disease/diverticulitis): Inflammation of diverticula with complications. Either the intestinal wall is perforated openly or there is a covered perforation (meaning an abscess has formed)
• Stage/Type 3 (chronic diverticular disease/diverticulitis): The condition is chronic and leads to persistent or recurring symptoms. Complications such as fistulas (abnormal channels) or strictures (narrowings) may also develop
• Stage/Type 4: Bleeding from the diverticula

A modern lifestyle is considered a major risk factor. A diet low in fiber leads to harder stools, which increases pressure on the intestinal wall. Excessive consumption of red meat, as well as obesity and lack of exercise, also contribute to diverticular disease. The guidelines of the German Society for Gastroenterology, Digestive and Metabolic Diseases also identify smoking as a factor that increases the risk of complicated diverticulitis.

According to the professional society’s guidelines on diverticular disease, modifiable risk factors for the development of diverticulitis include

• the consumption of red meat,
• smoking,
• being overweight, and
• certain underlying conditions, such as hypertension.

If diverticulitis is suspected, the first step is a physical examination, during which the doctor checks for tenderness and muscle guarding. However, the most important tool for diagnosing diverticulitis is an ultrasound or a CT scan of the abdomen. These procedures can clearly visualize the inflamed diverticula and the affected section of the intestine. A colonoscopy should be avoided during the acute phase, as the risk of perforation is too high.

In addition to

• the medical history (patient interview regarding symptoms, past illnesses, and medications taken),
• blood tests for elevated inflammatory markers (C-reactive protein = CRP, white blood cells), and
• a physical examination (such as palpation of the abdomen and a digital rectal exam)

imaging studies are important for diagnosing diverticulitis. Ultrasound and computed tomography (CT) scans can visualize the diverticula.

A colonoscopy should only be performed during a period when there is no inflammation. Otherwise, there would be an increased risk of bowel injury (perforation) in cases of diverticulitis. The colonoscopy is primarily used to

• assess diverticular bleeding and, if possible, stop it immediately, as well as
• rule out malignant conditions.

Specialists in the treatment of diverticulitis include physicians specializing in internal medicine and gastroenterology (gastrointestinal diseases) as well as visceral surgeons who perform bowel surgeries.

Primary care physicians can treat most mild cases on an outpatient basis. Severe cases, however, must be treated as inpatients at specialized clinics for diverticulitis, typically gastroenterology or visceral surgery departments.

Depending on the severity or stage of the disease, various treatment options are available. Conservative measures such as dietary changes, antibiotic therapy, and mesalazine are used for milder cases.

Surgery is required for stages of the disease

• that do not respond to conservative measures or
• in which complications such as an abscess or bowel perforation have occurred, or
• where there is an increased risk of recurrence or complications.

Mild symptoms, such as irregular bowel movements, can often be successfully treated by regulating bowel movements.

Antibiotic therapy is not initially necessary for acute but uncomplicated diverticulitis. However, this is contingent on there being no increased risk of complications. Close monitoring of the patient is required, however.

The risk of complications (perforation or abscess) is increased in patients with various pre-existing conditions, including

• hypertension (high blood pressure),
• chronic kidney disease,
• those undergoing immunosuppression, or
• those with an allergic predisposition.

In such cases, the doctor will prescribe antibiotic therapy. While taking antibiotics, the intestines should be “spared.” Therefore, a low-fiber diet is recommended during treatment. Once the inflammation has healed, the patient should switch back to a high-fiber diet.

Patients with acute complicated diverticular disease/diverticulitis should be treated as inpatients in a hospital.

If there is no improvement with antibiotic therapy, surgery should be performed. Abscesses can usually be drained by puncture or drainage.

Severe cases must be operated on immediately by an experienced abdominal surgeon (emergency surgery). A severe case is characterized by bowel perforation or peritonitis (inflammation of the peritoneum).

Even patients at this stage who have been successfully treated with antibiotics are advised to undergo surgery during the inflammation-free phase.

Under certain circumstances, it may be advisable to surgically remove the sections of the intestine containing diverticula during the inflammation-free interval. Removal is particularly advisable in cases of recurrent diverticulitis, but also in cases of frequent mild inflammation.

Stenoses are treated surgically when the narrowing leads to an obstruction of bowel movement. Fistulas should also be treated surgically. 

Recent studies show that quality of life in patients with recurrent inflammation improves significantly more after surgery than with regular antibiotic use.

Most cases of intestinal bleeding stop on their own. If this is not the case, the bleeding must be stopped. This can be done either

• during a colonoscopy,
• angiographically (i.e., via a blood vessel), or
• surgically

.

Procedures can be performed during a colonoscopy © sakurra | AdobeStock

scarring, which can lead to an intestinal obstruction.

Surgery for diverticulitis becomes necessary when complications such as a bowel perforation or a large abscess occur. Surgical treatment may also be advisable in cases of recurrent flare-ups that severely impair quality of life. In general and visceral surgery, procedures are now mostly performed using minimally invasive techniques. During the procedure, the inflamed section of the intestine is removed, and the healthy ends are sutured back together.

The course of diverticulitis can vary greatly. Inflammation of the diverticula often occurs in episodes. This means that after symptoms subside, inflammation recurs. Depending on the severity, this affects between 2 and 35 percent of patients who have had a single episode of diverticulitis.

Most patients with diverticula remain asymptomatic. In some, however, intestinal perforation can occur as early as the first flare-up. Other patients, on the other hand, do not develop complications even with recurring flare-ups.

The risk of bowel perforation is highest during the first flare-up; with each subsequent flare-up, the risk decreases. However, the risk of another recurrence also increases with each flare-up.

After a sigmoid resection, diverticula or diverticulitis may develop again in other sections of the intestine.

• Regular physical activity,
• adequate fluid intake,
• maintaining a healthy weight, and
• a high-fiber, vegetarian diet

are recommended to prevent diverticulitis.

What can you eat if you have acute diverticulitis?

During an acute flare-up, a low-fiber diet or bland diet is often recommended to relieve the intestines. As soon as the inflammation of the diverticula subsides, the transition to a high-fiber diet begins for long-term prevention.

Is diverticulitis always a medical emergency?

Not every form of diverticulitis is an emergency. Uncomplicated diverticulitis can often be treated effectively at home. However, if you experience severe pain, a high fever, or a hard abdomen, you should see a doctor immediately, as there may be a risk of a bowel perforation.

Can diverticulitis be cured without surgery?

Yes, most cases can be cured with conservative treatment involving medication and dietary adjustments. Surgery is only indicated in cases of complications or very frequent relapses.

How does diverticulitis differ from irritable bowel syndrome?

While diverticulitis is a detectable inflammation accompanied by fever and elevated blood test results, irritable bowel syndrome is a functional disorder with no organic findings.

Why do older people in particular have diverticula?

As people age, the elasticity of the intestinal wall decreases. Combined with long-standing dietary habits, this leads to diverticula being very common in the large intestine among people over 60.

Is blood in the stool a symptom of diverticulitis?

Yes, bleeding from a diverticulum can occur, often even without pain. However, since blood in the stool can also indicate colorectal cancer, this must always be evaluated by a doctor.

Does exercise help prevent diverticula?

Exercise improves bowel motility and prevents constipation. This reduces pressure on the intestinal wall, which makes it harder for diverticula to form and lowers the risk of inflammation.

How long does treatment in the hospital take?

If you’re admitted to the hospital for complicated diverticulitis, you should expect to stay for about 5 to 10 days, depending on how quickly the inflammation responds to antibiotics.