Colorectal cancer starts in the colon or the rectum. These cancers can also be called colon cancer or rectal cancer, depending on where they start. Colon cancer and rectal cancer are often grouped together because they have many features in common.
Cancer starts when cells in the body start to grow out of control.
The colon absorbs water and salt from the remaining food matter after it goes through the small intestine (small bowel). The waste matter that’s left after going through the colon goes into the rectum, the final 6 inches (15cm) of the digestive system. It’s stored there until it passes through the anus. Ring-shaped muscles (also called a sphincter) around the anus keep stool from coming out until they relax during a bowel movement.
There are several reasons that people may require a surgeon to help alleviate conditions related to their rectum and/or anus. For example, patients may develop an anal fissure (a small tear), an abscess or fistula (an infection), hemorrhoids, anal condyloma, or pruritis ani. A colorectal surgeon can help safely examine a concern in that area and, if surgery is required, perform a procedure.
Some of the leading causes of anorectal disorders are polyps, inflammatory bowel disease, pregnancy and childbirth, manual irritation of the area, underlying skin conditions, and infections.
During the diagnostic stage, a surgeon may perform a digital rectal exam (a manual exploration to detect abnormalities) and biopsy to collect a sample of tissue for testing. A surgeon may request additional noninvasive imaging tests, such as an ultrasound or MRI, to review functionality and structure.
A surgeon may perform an anoscopy, which is a diagnostic procedure in which a small tubular instrument is used to view the rectum and anal canal. If the surgeon suspects that the problem may go further into the colon, a colonoscopy or flexible sigmoidoscopy may be scheduled. These procedures are performed under mild sedation and a flexible tube with a camera is inserted into the anus and gently guided upwards into the colon or intestine. These are minimally invasive procedures and require little recovery time.
The lining of the digestive system can form small, bulging pouches called diverticula. Most people will develop these small pouches in their lifetime. For some, these pouches can become inflamed and lead to a condition called diverticulitis. This can lead to serious complications including pain, fever, scarring, changes in frequency of bathroom visits, and/or blockages.
Some mild cases of diverticulitis can be corrected non-surgically. Severe or recurring diverticulitis can require surgical intervention. Diverticular disease surgery can include a primary bowel resection where the surgeon removes diseased segments of the intestine and reconnects healthy segments. This is often done as a minimally invasive laparoscopic procedure. If the diverticular disease is extensive or impacts the bowel in a way that the colon and rectum cannot be connected, the surgeon will perform a colostomy. During a colostomy, the surgeon creates an opening in the abdominal wall and securely fits a device over the opening. Waste that normally is passed through the colon will be routed out the device into a collection system. Sometimes a colostomy is temporary or permanent. If the colostomy is temporary, a second surgery is required to rejoin the bowel and remove the device.
Additional surgeries may be required if other diverticula pouches appear and become inflamed and/or painful.