Colonic diverticulum refers to a diverticulum-like lesion formed by the herniation of the colonic mucosa through the defect of the circular muscle layer of the intestinal wall. It can occur in any part of the intestine, and the most common site is the colon, followed by the duodenum. Typical symptoms of diverticulitis include abdominal pain, fever, nausea, vomiting, abdominal distension, constipation, and diarrhea. Since the sigmoid colon is the most common site of diverticulum, abdominal pain is mostly in the lower abdomen, especially the left lower abdomen. It can also be manifested in the midline of the lower abdomen or in the right lower abdomen depending on the location of the diverticulum. The severity of the pain varies depending on the degree of inflammation.