Lower abdominal pain usually requires laboratory tests, imaging tests, and sometimes colonoscopy and pathological tests. Laboratory tests usually require routine blood tests, C-reactive protein, liver function, hepatitis B five, infection four, and sometimes tumor marker tests, such as CA19-9, CA12-5, methemoglobin, carcinoembryonic antigen, etc. Imaging examination usually requires abdominal ultrasound, or abdominal CT, abdominal MRI, etc. Sometimes, enhanced scan or contrast examination is also required. If a problem in the colon is considered, it usually requires oral laxatives followed by colonoscopy, and some patients may need PET-CT to help clarify the diagnosis. If a significant local mass is found, a puncture biopsy may be performed, or the mass may be removed and then a pathological biopsy may be done to clarify its nature.