Diagnosis of diverticulitis starts by recording patient history and performing a physical examination. Laboratory tests are important in excluding other causes of abdominal pain and any other gastrointestinal disease. These laboratory tests include complete blood count (CBC), C-reactive protein (CRP), urinalysis, and liver function tests. Imaging studies including CT scan and colonoscopy are also important measures in diagnosing diverticulitis.^[1][2]

The initial diagnostic measures for diverticulitis are taking a proper history, doing a physical exam, and performing laboratory tests. Laboratory tests are initially necessary to exclude other gastrointestinal diseases and confirm diverticulitis. These lab tests include the following:

• C-reactive protein (CRP) – elevated due to inflammation
• Complete blood count (CBC)- CBC may show leukocytosis. A normal white blood cell count does not exclude diverticulitis, as most patients suffering from diverticulitis have normal blood cell counts.
• Urinalysis: Urinalysis is performed especially in cases complicated by fistula and may show the following findings:^[3]
  • Pyuria– In the case of urinary tract infection
  • Hematuria– In the case of nephrolithiasis
• Liver function tests- Amylase and lipase levels should be checked to exclude other diseases that cause abdominal pain.