rectal
Meaning of rectal: One word doing two jobs: it either places a finding at the end of the bowel or names how a medicine was given.
Definition of rectal
Rectal describes anything relating to the rectum, the last segment of the large intestine, sitting between the sigmoid colon and the anus. The word does two jobs in medical writing. It marks an anatomic location, as in rectal bleeding or rectal exam, and it names a route of administration, as in a rectal suppository.
How rectal is built
- rect/o Combining form · Latin rectum
- -ac, -al, -ar, -ary, -eal, -ic Suffix · Greek and Latin pertaining to, relating to
A medical term is read from its ending backwards: the suffix first, then the prefix, then the root. See all 223 word parts.
What does rectal describe anatomically?
The rectum is the final stretch of the large intestine, sitting deep in the pelvis just above the anus. Any finding placed there takes the adjective. Rectal bleeding means blood appearing from that end of the tract, though the source may lie much higher up, since blood travels downstream. A rectal examination means a gloved finger inserted to feel the rectal wall and the structures immediately beside it, including the prostate in men. Rectal pain, rectal urgency and the sense of incomplete emptying all describe symptoms localized to this segment. Rectal tone and rectal sensation are assessed when nerve injury is suspected, since the nerves supplying the rectum travel with those supplying the bladder and legs.
Why give a medicine by this route?
The rectal lining is thin and richly supplied with blood vessels, so a drug placed against it can be absorbed without being swallowed. That makes the route useful when someone is vomiting, unconscious, unable to swallow, or too young to manage a tablet. A suppository is a solid preparation shaped to melt at body temperature; an enema is a liquid instilled into the rectum. Some rectal preparations are not meant to be absorbed at all, and instead act on the rectal lining itself.
How does the route change what happens to a drug?
| Taken by mouth | Given rectally | |
|---|---|---|
| Path taken | Stomach and small intestine, then the liver, then the circulation | Rectal veins, with part of the flow bypassing the liver |
| Effect of vomiting | The dose may be lost | Unaffected |
| Predictability | Generally consistent | More variable, depending on placement and on stool present |
| Local action possible | No | Yes, for conditions of the rectal lining |
Because part of the blood draining the lower rectum reaches the general circulation without first passing through the liver, some drugs reach higher levels by this route than the same amount swallowed would produce, while others do not. The adjective also appears in disease names such as rectal cancer, where it identifies the segment involved rather than any route of delivery.
Used in a sentence
A rectal suppository was given after the patient was unable to tolerate oral medication.
Good to know
Rectal can describe an anatomic location, as in rectal bleeding, or a route of drug delivery, as in a rectal suppository, and the intended meaning is usually clear from the surrounding context.