STRUCTURE AND POSITION

• Rectum starts at the level of S3 vertebra where Sigmoid Colon ends. Its as wide as sigmoid colon at its start.
• Rectum ends with a dilated portion called Rectal Ampulla. It connects here to Anal canal.
• Rectum is 12-15 centimetres in length.
• Rectum is covered in upper two third by peritoneum anteriorly, And in lower one third by Pelvic Fascia.

BLOOD SUPPLY AND LYMPHATICS

Blood to rectum is supplied by Superior and Middle Rectal Vessels. Lymph is drained into Pararectal, Inferior Mesenteric, Deep Inguinal, and Internal Iliac Lymph Nodes.

NERVE SUPPLY

Rectum is innervated via Inferior Anal nerves and Inferior Mesenteric Ganglia.

FUNCTION

•    Rectum stores faeces for some time at the end of digestion and absorption.
•    Dilation by faeces then evokes defecation reflex by activating stretch receptors in its walls.
•    During defecation it contracts and helps passing down the stools.

CLINICAL IMPORTANCE

• Rectal Examination is an important technique used in diagnosis of various diseases.
• Rectal Temperature is an important clinical sign specially in children and regarded more significant than oral temperature.
• Anema and Suppositories are given via anal route enter rectum first and then go to proximal portion.
• Rectal Prolapse is an important disease condition in which rectum gets protruding and out through anus.
• Rectum gets inflamed and infected in many important diseases like Inflammatory bowel disease and Ulcerative Colitis.