Signs and Symptoms of Diverticulitis
Diverticulitis describes inflammation and infection usually associated with the large intestine (colon), where small outpouchings in the colon wall called diverticuli are present. These tiny pouches develop over time, are frequently associated with chronic constipation, and are often found in older adults. When they are found to be present, it is called diverticulosis. When one diverticulum gets inflamed, it can develop a microscopic hole or leak, called a microperforation, letting a small amount of stool and/or air escape from the colon. A local infection then occurs against the colon wall, which is called diverticulitis. Most diverticuli are found toward the end of the bowel in the descending (left) and sigmoid colon (S-shaped part just before the rectum), but they can occur in any part of the intestine. Thus, the inflammation from diverticulitis usually causes pain in the left lower quadrant of the abdominal cavity. Diverticulitis can cause the colon to stop working well, leading to constipation, or to work too fast, causing diarrhea. Some patients feel hot and have temperatures higher than normal. Some patients experience chills instead, and feel cold or have shivers, when others around them do not. Sometimes, it is possible to feel chilled and have a fever at the same time. You may also feel sick enough to have nausea or vomiting.
Most often, the tiny hole in the colon that led to the diverticulitis seals over, as the body works to contain the infection by walling off the contaminated area with nearby fat and other parts of the intestine. Sometimes this process leads to an organized collection of infected fluid, or pus, called an abscess, usually right next to the affected colon or down in the pelvis. Pain with movement or shaking of the abdomen is an indicator of peritonitis, or inflammation of the peritoneum—the abdominal lining. This can occur just in the local area, or it may indicate the spread of infection to other parts of the abdomen. If the hole in the colon does not seal quickly, or is large, more gas may come out of the bowel along with stool and infected fluid, leading to abdominal distention, increased pain and generalized peritonitis.
Diagnosis of Diverticulitis
The doctor will take a careful history, asking about when and how your symptoms started, like pain, fever, diarrhea or vomiting, and whether there have been changes since they started. A physical examination enables your doctor to evaluate for presence, location and degree of tenderness, and blood is drawn to check labs related to infection, dehydration and other possible causes of your symptoms. Imaging will be performed, most commonly a CT scan, which can show the doctor if diverticulitis is present, and whether there is an associated abscess. Tiny bubbles of air confined to the affected area may be present, but if there is “free air” identified away from the colon (bowel perforation), or a larger amount of it, surgery may be required emergently. Diverticulitis may be referred to as simple, or uncomplicated, which means there is inflammation but no abscess or free air. Complicated diverticulitis includes cases with abscess, and/or a larger perforation (hole) requiring intervention.
Treatment for Diverticulitis
Intravenous fluids, antibiotics, pain medication and bowel rest are the mainstays of treatment for uncomplicated diverticulitis. Very mild cases may be treatable with oral antibiotics and a liquid diet at home, but many patients stay in the hospital initially for IV antibiotics and monitoring. In the hospital, the doctor will watch carefully for any signs of sudden or increasing pain, fever or labs suggesting that you are getting worse instead of better, and may need surgery after all. When the pain and tenderness have gone away, liquids and then a low-fiber diet may be resumed. Once the patient is tolerating food and taking only oral pain medicine as needed, antibiotics may be switched to oral as well to complete the course at home. After recovery, in a couple of weeks, patients should work back to a high-fiber diet with plenty of fluids, to minimize constipation. Colonoscopy should be performed 6-8 weeks after recovery, regardless of the patient’s age, to confirm the presence of diverticulosis, and to make sure no other abnormalities are found. It may not be possible to tell the difference between diverticulitis and perforated colon cancer on imaging alone.
Diverticulitis complicated by abscess will need drainage of the infected collection. In many cases, this may be done by an Interventional Radiologist, with CT guidance. A small drainage tube is inserted through the skin, after numbing the area, and attached to a collection bag or bulb. Cultures are sent of the fluid to guide antibiotic therapy. The drain will stay in place until the fluid turns clearer and a minimal amount is emptied on a daily basis. Repeat imaging may be done to ensure that the abscess has been evacuated before the drain is removed. If the abscess cannot be reached safely in this manner, surgery may be necessary.
When surgery is performed for diverticulitis associated with perforation, or an abscess that radiology cannot drain, the affected area of the colon is usually removed in an operation called a Hartmann’s procedure. This is most often the sigmoid colon, but in some cases, it can be another part of the colon or intestine. An anesthesiologist puts the patient to sleep for the operation, and wakes them up afterward. An incision is made in the abdomen for the surgeon to look inside. Once the hole in the colon is identified, and the affected portion has been removed, all of the infected fluid and any stool contamination is washed out. In most cases, because of this contamination, the two ends of the colon cannot be reconnected during this operation and expected to heal without falling apart. The surgeon will then create a colostomy, or an opening in the abdominal wall, where the free upper end of the colon is brought through and sutured to the skin. A special bag is placed over the opening, or stoma, for stool to collect in. The abdominal incision will be left open or partly open, with gauze packing tucked into the wound, which will be changed daily. This is because the wound is likely to get infected if it is closed up tightly; the open areas will heal over time, from the inside out, with dressing changes. The patient will learn how to care for the colostomy, and a visiting nurse may come to the patient’s home to help with wound and colostomy care.
Once the patient has recovered from their infection and operation, the colostomy may be reversed at some point in the future, depending on that patient’s individual circumstances and operative risks. Most surgeons will wait 3-6 months to allow healing inside the abdomen before considering reversal, but each patient’s case is unique. This requires another operation to reconnect the ends of the bowel, and a period of time in the hospital for recovery. At that time, the surgeon will leave open a smaller wound, where the ostomy was, to heal with dressing changes. This time, though, the main incision will be closed, and the surgeon might even be able to revise the old scar, leaving less of a scar in its place.