By far, the commonest indication for abdominal plain film radiography is abdominal pain. In examining an abdominal plain film, it is often helpful to have a systematic approach because many findings are subtle and easily overlooked. An upright chest or abdominal radiograph should include the diaphragms, which should be checked for abnormal subphrenic radiolucencies. Splenic enlargement due to trauma or medical disease may be suggested by displacement of the splenic flexure, gastric bubble, or left kidney. Linear radiolucencies in the liver indicate gas in the biliary or portal systems. This finding associated with small bowel obstruction suggests gallstone ileus. A variety of abnormal radio densities can be encountered on plain films. Most are due to abnormal calcifications within the soft tissues, although they can also be caused by foreign bodies, surgical clips, pills, or intramuscular injections. Plain films are rarely indicated in the evaluation of gastrointestinal hemorrhage or gastroenteritis.

Colorectal cancer is the second most common cancer and the third most common cause of cancer death in women. Fecal occult blood testing (FOBT), sigmoidoscopy, colonoscopy, and a combination of these three methods are all considered valid screening methods. Screening after the age of 50 is suggested because of the prevalence of colon cancer in this age group. Between 5% and 10% of colon cancer has an inherited base, although only a few mutated genes are known. Colon cancer can be asymptomatic or may appear as iron-deficient anemia, gastrointestinal hemorrhage, change of bowel habits or constipation. The most common cause of lung cancer is smoking, which accounts for 90% of lung cancers. Surgery, radiation, and chemotherapy are the treatments, with surgery being the treatment of choice if the cancer is local. Excessive exposure to radiation, excessive tanning and burning, and fair complexion are risk factors for skin cancer.