Diverticulitis is a gastrointestinal condition characterized by the inflammation of small, bulging pouches, called diverticula, that form in the wall of the large intestine. While the majority of cases involve the left side of the colon, right side diverticulitis (RSD) is a distinct presentation that primarily affects the ascending colon and the cecum. Understanding this variation is important because its clinical presentation and management can differ significantly from the more common left-sided disease. RSD presents unique challenges to diagnosis due to its location and the conditions it closely resembles.
Anatomical Differences and Prevalence
The anatomical location of the inflamed pouches is the primary feature distinguishing right side diverticulitis from the typical form. Left-sided diverticulitis most frequently occurs in the sigmoid colon, the final segment of the large intestine before the rectum. In contrast, right side diverticulitis involves the ascending colon and the cecum, which is the beginning of the large intestine in the lower right abdomen.
The structure of the diverticula also shows a difference between the two forms of the disease. The diverticula on the right side are often “true” diverticula, meaning they are congenital and involve all layers of the intestinal wall, including the muscle layer. Conversely, the pouches in left-sided disease are usually “false” or pseudodiverticula, which are acquired and involve only the inner lining layers that have herniated through a weakness in the muscular coat.
Epidemiologically, the distribution of the disease varies greatly by geography and age. Left-sided diverticulitis is the most common form in Western populations and tends to affect older individuals. Right side diverticulitis is seen much more frequently in Asian populations, where it may account for a majority of diverticulitis cases. It is also often found in younger individuals compared to the typical profile of left-sided disease.
Symptoms and Mimicry of Other Conditions
The symptoms of right side diverticulitis are often misleading, which makes accurate and timely diagnosis difficult. The main symptom is abdominal pain, which is concentrated in the right lower quadrant (RLQ) of the abdomen. This location of pain is the same area commonly associated with acute appendicitis, leading to frequent misdiagnosis.
The clinical presentation of RSD can closely mimic appendicitis, creating a diagnostic dilemma for healthcare providers. Patients may also experience a fever, nausea, and vomiting, further supporting the suspicion of an inflamed appendix. Localized tenderness upon examination of the right lower abdomen is a common finding in both conditions.
The pain from right side diverticulitis can sometimes be more generalized or located slightly more laterally or superiorly than the pain of appendicitis, but this distinction is not always reliable. Due to this significant overlap in symptoms, it is difficult to differentiate RSD from appendicitis based on physical examination and laboratory work alone. Laboratory tests usually show signs of inflammation, such as an elevated white blood cell count.
Diagnostic Methods
Due to the high degree of symptom overlap with appendicitis, imaging is necessary to confirm a diagnosis of right side diverticulitis. Abdominal Computed Tomography (CT) scanning is considered the gold standard for definitively diagnosing diverticulitis and ruling out other conditions. The CT scan provides detailed images that can show the characteristic signs of RSD, including localized thickening of the colon wall and inflammation extending into the surrounding fatty tissue.
The CT scan is also used to identify any complications, such as an abscess or perforation, which would affect the treatment plan. In addition to CT, an ultrasound may be used as an initial imaging tool, especially for younger patients where minimizing radiation exposure is a concern. Ultrasound can often detect the thickened bowel wall and surrounding inflammation.
Laboratory tests complement the imaging results by providing evidence of infection and inflammation. A complete blood count is performed to check for an elevated white blood cell count, which suggests an active inflammatory process. Other tests, such as a urine analysis, may be ordered to exclude urinary tract issues that could also cause right lower quadrant pain.
Treatment Protocols
The management of right side diverticulitis frequently follows a less aggressive course than left-sided disease, especially in uncomplicated cases. Most patients with uncomplicated RSD are treated conservatively, which includes bowel rest and supportive care. Bowel rest typically involves a clear liquid diet, which can be advanced gradually to low-fiber foods as symptoms improve.
Antibiotics are often prescribed, though recent guidelines suggest a selective approach for mild, uncomplicated cases. When antibiotics are used, they are intended to cover the types of bacteria commonly found in the colon. The generally benign nature of RSD means that symptoms often resolve quickly with this conservative treatment, sometimes within a few days.
Hospitalization is reserved for patients with more severe symptoms, an inability to tolerate liquids by mouth, or signs of complicated disease. Surgery is generally not the first line of treatment and is reserved for complicated cases, such as those involving a large abscess, perforation, or a failure of medical management. Unlike left-sided disease, where elective surgery is common after multiple recurrences, surgery for RSD is less frequently needed due to its lower rate of recurrence and milder course.