The descending colon of humans passes downward through the left hypochondrium and lumbar regions, along the lateral border of the left kidney. The descending colon is a part of the large intestine. The large intestine includes the vermiform appendix, the cecum and the colon. The descending colon is a part of the colon, which is made up of several parts. They include the ascending colon, hepatic flexure, transverse colon, splenic flexure, descending colon, and sigmoid colon. The descending colon passes down through the upper back portion of the abdomen and along the side of the left kidney. The large intestine functions as a reservoir for liquid that is deposited from the small intestine. The large intestine is responsible for the absorption of water and other substances, such as salts. It also stores waste until it can be removed from the body when a person has a bowel movement. As food moves through the intestinal tract, water is absorbed by the large intestine. This causes the waste to leave the body in solid form. It is important to maintain good colon health, as there are several diseases associated with the descending colon. Among the most common are ulcerative colitis, Crohn’s disease, and colon cancer. Ulcerative colitis can affect any part of the colon, but when it affects the descending colon, it is called left-sided colitis. Inflammation and ulcers on the lining of the intestine mark its presence. Symptoms of ulcerative colitis include diarrhea, bleeding, fever, abdominal pain, too much mucus in fecal material, and appetite and weight loss. Treatment methods can vary widely, ranging from changes in diet to corrective surgery, depending on the severity of the condition and the overall health of the patient. When a person has Crohn’s disease or Crohn’s colitis, he has sores on the tissues of the intestine; this makes it hard for the intestine to absorb water and salt. The symptoms that may develop from this disease include abdominal pain, diarrhea or constipation, nausea and vomiting, fever, blood in the stool, weight loss, abscesses and fatigue. There is no cure for Crohn’s disease; only dietary changes can help to make the symptoms less severe. Cancer of the descending colon is the most serious of the diseases. A person can have colon cancer yet have no symptoms in the early stages. As such, regular colorectal examinations are necessary for catching the disease in its early stages. However, there are some signs that can indicate colon cancer; they include abrupt changes in bowel habits, bleeding from the rectum, black stools, frequent constipation, and mucus in the stools. Treatment options depend on the stage of the cancer and the overall health of the patient.