A fecal impaction is a solid, immobile bulk of feces that can develop in the rectum as a result of chronic constipation. A related term is fecal loading which refers to a large volume of stool in the rectum of any consistency. Fecal impaction is a common result of neurogenic bowel dysfunction and causes immense discomfort and pain. Treatment of fecal impaction includes laxatives, enema, and pulsed irrigation evacuation (PIE). Signs and symptoms
Symptoms include chronic constipation. There can be fecal incontinence and paradoxical overflow diarrhea (encopresis) as liquid stool passes around the obstruction. Complications may include necrosis and ulcers of the rectal tissue. Abdominal pain and bloating could also be present depending on the severity of the condition. Loss of appetite can also occur. Causes
There are many possible causes; for example, physical inactivity, not eating enough fiber, dehydration, and holding in bowel movements. Medications such as opioid pain relievers (fentanyl, buprenorphine, methadone, codeine, oxycodone, hydrocodone, morphine, hydromorphone, etc.) and certain sedatives that reduce intestinal movement may cause fecal matter to become too large, hard and/or dry to expel. Specific conditions, such as irritable bowel syndrome, certain neurological disorders, paralytic ileus, gastroparesis, diabetes, dehydration, enlarged prostate gland, distended colon, ingested foreign object, inflammatory bowel diseases such as Crohns disease and colitis,  and autoimmune diseases such as amyloidosis, celiac disease, lupus, and scleroderma can cause constipation. Hypothyroidism can cause chronic constipation because of sluggish, slower, or weaker colon contractions. Iron supplements or increased blood calcium levels are also potential causes.
Levorphanol (brand name Levo-Dromoran) is an opioid medication used to treat moderate to severe pain. It is one of two enantiomers of the compound racemorphan. It was first described in Germany in 1946. The drug has been in medical use in the United States since 1953. Pharmacology
Levorphanol acts predominantly as an agonist of the μ-opioid receptor (MOR), but is also an agonist of the δ-opioid receptor (DOR), κ-opioid receptor (KOR), and the nociceptin receptor (NOP), as well as an NMDA receptor antagonist and a serotonin-norepinephrine reuptake inhibitor (SNRI). Levorphanol, similarly to certain other opioids, also acts as a glycine receptor antagonist and GABA receptor antagonist at very high concentrations. Levorphanol is 6 to 8 times as potent as morphine at the MOR.Relative to morphine, levorphanol lacks complete cross-tolerance and possesses greater intrinsic activity at the MOR. The duration of action is generally long compared to other comparable analgesics and varies from 4 hours to as much as 15 hours. For this reason levorphanol is useful in palliation of chronic pain and similar conditions. Levorphanol has an oral to parenteral effectiveness ratio of 2:1, one of the most favorable of the strong narcotics. Its antagonism of the NMDA receptor, similar to those of the phenylheptylamine open-chain opioids such as methadone or the phenylpiperidine ketobemidone, make levorphanol useful for types of pain that other analgesics may not be as effective against, such as neuropathic pain.