Hemorrhoids: This condition is the most common cause of fresh blood clots in stool, especially if the blood is bright red and the clots are small. Hemorrhoids can cause significant bleeding, especially during bowel movements.

Anal Fissure: A tear in the lining of the anus can cause pain and bleeding during bowel movements, potentially leading to the passage of fresh blood clots.
Diverticulitis: Inflammation of the diverticula in the colon can lead to bleeding, which may appear as fresh blood clots in the stool.
Colon Polyps or Cancer: These conditions can cause bleeding in the colon, which may be visible as fresh blood clots in the stool during bowel movements.

Lower Gastrointestinal Bleeding from Angiodysplasia or Arteriovenous Malformations: Although less common, these vascular abnormalities can cause significant, potentially life-threatening bleeding.
Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis can cause chronic inflammation and bleeding in the gastrointestinal tract, which may present with fresh blood clots in the stool.
Infectious Colitis: Certain infections can cause inflammation and bleeding in the colon, leading to the passage of blood and clots during bowel movements.

Intussusception: A condition where a part of the intestine slides into an adjacent part, potentially causing bowel obstruction and bleeding.
Meckel's Diverticulum: A congenital anomaly of the small intestine that can cause bleeding due to the presence of ectopic gastric mucosa.
Colonic Varices: Enlarged veins in the colon, often associated with liver disease, can rupture and cause significant bleeding.