Hemorrhoids: This condition is characterized by swollen veins in the lowest part of the rectum or anus. Symptoms include painful bowel movements, especially if the hemorrhoids are thrombosed, and the presence of a small amount of blood and mucus. The pain and bleeding are typically more pronounced during and immediately after defecation.

Anal Fissure: A small tear in the lining of the anus, which can cause sharp pain during and after bowel movements. Blood and mucus may be present, especially if the fissure becomes infected.
Proctitis: Inflammation of the rectum, which can be caused by infections, allergies, or irritation from stool. Symptoms include pain during bowel movements, discharge (which may include mucus and blood), and a feeling of urgency.
Diverticulitis: Inflammation or infection of small pouches (diverticula) in the wall of the intestines. While it more commonly presents with left lower quadrant abdominal pain, changes in bowel habits, and possibly blood in the stool, it could also cause painful bowel movements with mucus and blood in some cases.

Colorectal Cancer: Although less common, especially in younger individuals, colorectal cancer can present with changes in bowel habits, including painful bowel movements, and blood in the stool. The presence of mucus could be indicative of a tumor affecting bowel function.
Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis can cause chronic inflammation of the gastrointestinal tract, leading to symptoms such as abdominal pain, changes in bowel habits, blood in the stool, and mucus. These conditions require prompt diagnosis and treatment to prevent complications.
Infectious Colitis: Certain bacterial, viral, or parasitic infections can cause inflammation of the colon, leading to symptoms including painful bowel movements, blood, and mucus in the stool. Identifying and treating the underlying cause is crucial.

Solitary Rectal Ulcer Syndrome: A condition characterized by the presence of an ulcer in the rectum, often associated with chronic constipation and straining during bowel movements. It can cause rectal bleeding, mucus discharge, and pain.
Rectal Prolapse: A condition where the rectum loses its normal attachments inside the body, allowing it to protrude out through the anus. This can cause a variety of symptoms, including pain, bleeding, and mucus discharge, especially during bowel movements.