Investigations in Appendicitis help in ruling out other diagnosis for the cause of pain.

Investigations are done for two purposes –

1. Before subjecting the patient for any anesthetic and surgical procedure – to ensure that the surgery can be done safely.

2. To rule out other diagnosis if there is any element of doubt.

Accordingly the following investigations may need to be carriesd out-

 Blood test. This allows the doctor to check for a high white blood cell count, which may indicate an infection.

 Urine test. A urinalysis helps to rule out conditions like urinary tract infection or a kidney stone, which can cause abdominal pain. If it is a kidney stone, red blood cells are usually seen during microscopic examination of the urine.

Appendicits pain can be mimicked by many similar conditions like gall stones, inflammation of gall bladder ( Cholecystitis), stone in the lowe section of the ureter, ruptured ovarian follicle during the middle of the menstrual period, a ruptured pregnancy of the right tube, a rupture or perforation of a ulcer in the stomach or duodenum or due to inflammation of the right colon. If in doubt imaging studies are warranted to rule out these conditons.

 Imaging tests are also used when making an appendicitis diagnosis. X-rays, Ultrasounds, and Computed Axial Tomography (CAT) scans are used to produce images of the abdomen.

X-rays - An x-ray can rule out signs of obstruction or perforation (a hole) of the GUT as cause of pain. In rare cases, an appendicolith, which is hardened stool in the appendix, may be found and seen on the X-ray.

Ultrasound- An ultrasound may show appendiceal inflammation, gallbladder disease, and pregnancy.

CAT scan- The most common and reliable imaging test that is used to diagnose appendicitis is currently the CAT scan. The CAT scan is excellent if there is doubt regarding the nature of the pain as it can identify other common causes of pain in that region like - stone in the ureter, gall-stones, ruptured tubal pregnancy. In appendicitis it shows the inflamed appendix quite clearly.

It is important for women of childbearing age to have a pregnancy test before undergoing any testing with x-rays.