A short, muscular tube that forms the lowest part of the large intestine and connects it to the anus.
Rectal disorders are diagnosed by rectal examination and proctoscopy or by sigmoidoscopy.
The last part of the large INTESTINE. It pursues a more or less straight course downwards through the cavity of the pelvis, lying against the sacrum at the back of this cavity. This section of the intestine is about 23 cm (9 inches) long: its ?rst part is freely movable and corresponds to the upper three pieces of the sacrum; the second part corresponds to the lower two pieces of the sacrum and the coccyx; whilst the third part, known also as the anal canal, is about 25 mm (1 inch) long, runs downwards and backwards, and is kept tightly closed by the internal and external SPHINCTER muscles which surround it. The opening to the exterior is known as the ANUS. The structure of the rectum is similar to that of the rest of the intestine.
n. the terminal part of the large *intestine, about 12 cm long, which runs from the sigmoid colon to the anal canal. Faeces are stored in the rectum before defecation. —rectal adj.
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