Proctitis is an inflammation of the anus and the lining of the rectum, affecting only the last 6 inches of the rectum. Signs and symptoms
A common symptom is a continual urge to have a bowel movement—the rectum could feel full or have constipation. Another is tenderness and mild irritation in the rectum and anal region. A serious symptom is pus and blood in the discharge, accompanied by cramps and pain during the bowel movement. If there is severe bleeding, anemia can result, showing symptoms such as pale skin, irritability, weakness, dizziness, brittle nails, and shortness of breath.Symptoms are ineffectual straining to empty the bowels, diarrhea, rectal bleeding and possible discharge, a feeling of not having adequately emptied the bowels, involuntary spasms and cramping during bowel movements, left-sided abdominal pain, passage of mucus through the rectum, and anorectal pain. Sexually transmitted proctitis
Gonorrhea (Gonococcal proctitis)

This is the most common cause. Strongly associated with anal intercourse. Symptoms include soreness, itching, bloody or pus-like discharge, or diarrhea. Other rectal problems that may be present are anal warts, anal tears, fistulas, and hemorrhoids.Chlamydia (chlamydia proctitis)

Accounts for twenty percent of cases. People may show no symptoms, mild symptoms, or severe symptoms. Mild symptoms include rectal pain with bowel movements, rectal discharge, and cramping. With severe cases, people may have discharge containing blood or pus, severe rectal pain, and diarrhea. Some people have rectal strictures, a narrowing of the rectal passageway.
Piriformis syndrome
Piriformis syndrome is a condition that, depending on the analysis, varies from a "very rare" cause to contributing up to 8% of low back or buttock pain. In 17% of people, the sciatic nerve runs through the piriformis muscle rather than beneath it. When the piriformis shortens or spasms due to trauma or overuse, it is posited that this causes compression of the sciatic nerve. Piriformis syndrome has colloquially been referred to as "wallet sciatica" since a wallet carried in a rear hip pocket compresses the buttock muscles and sciatic nerve when the bearer sits down. Piriformis syndrome may be suspected as a cause of sciatica when the spinal nerve roots contributing to the sciatic nerve are normal and no herniation of a spinal disc is apparent. Endometriosis
Sciatic endometriosis, also called catamenial or cyclical sciatica, is a sciatica whose cause is endometriosis. Its incidence is unknown. Diagnosis is usually made by an MRI or CT-myelography. Pregnancy
Sciatica may also occur during pregnancy, especially during later stages, as a result of the weight of the fetus pressing on the sciatic nerve during sitting or during leg spasms. While most cases do not directly harm the woman or the fetus, indirect harm may come from the numbing effect on the legs, which can cause loss of balance and falls. There is no standard treatment for pregnancy-induced sciatica. Other
Pain that does not improve when lying down suggests a nonmechanical cause, such as cancer, inflammation, or infection.