Rectal diseases refer to conditions that affect the structure or function of the rectum, which is the lower end of the large intestine, just above the anus. The rectum serves as a storage area for stool before it is eliminated from the body. Some common rectal diseases include:

1. Hemorrhoids: Swollen veins in the rectum or anus that can cause pain, itching, bleeding, and discomfort.
2. Rectal cancer: Abnormal growth of cells in the rectum that can invade and destroy nearby tissue and spread to other parts of the body.
3. Anal fissures: Small tears in the lining of the anus that can cause pain, bleeding, and itching.
4. Rectal prolapse: A condition where the rectum slips outside the anus, causing discomfort, fecal incontinence, and other symptoms.
5. Inflammatory bowel disease (IBD): A group of chronic inflammatory conditions that affect the digestive tract, including the rectum, such as Crohn's disease and ulcerative colitis.
6. Rectal abscess: A collection of pus in the rectum caused by an infection, which can cause pain, swelling, and fever.
7. Fistula-in-ano: An abnormal connection between the rectum and the skin around the anus, which can cause drainage of pus or stool.
8. Rectal foreign bodies: Objects that are accidentally or intentionally inserted into the rectum and can cause injury, infection, or obstruction.

These are just a few examples of rectal diseases, and there are many other conditions that can affect the rectum. If you experience any symptoms related to the rectum, it is important to seek medical attention from a healthcare professional for proper diagnosis and treatment.