SF 6 is used as a contrast agent for ultrasound imaging. Sulfur hexafluoride microbubbles are administered in solution through injection into a peripheral vein. These microbubbles enhance the visibility of blood vessels to ultrasound.F 6 is used as a contrast agent for ultrasound imaging. Sulfur hexafluoride microbubbles are administered in solution through injection into a peripheral vein. These microbubbles enhance the visibility of blood vessels to ultrasound.
Once constipation (no bowel movement) has gone on for some time, the result can be what is known as an impacted bowel (sometimes called fecal impaction). Essentially, this means that a large lump of dry, hard stool is stuck inside your rectum.
Many people think of constipation as not passing a bowel movement every day. However constipation implies not only infrequent bowel movements, but also having difficulty in passing bowel movements and/or experiencing pain with the passage of stools.