Prevention
DNA-based tissue typing allows for more precise HLA matching between donors and transplant patients, which has been proven to reduce the incidence and severity of GvHD and to increase long-term survival. The T-cells of umbilical cord blood (UCB) have an inherent immunological immaturity, and the use of UCB stem cells in unrelated donor transplants has a reduced incidence and severity of GvHD. Methotrexate, cyclosporin and tacrolimus are common drugs used for GvHD prophylaxis. Further research is necessary to evaluate whether mesenchymal stromal cells can also be used for the prophylaxis. Graft-versus-host disease can largely be avoided by performing a T-cell-depleted bone marrow transplant. However, these types of transplants come at a cost of diminished graft-versus-tumor effect, greater risk of engraftment failure, or cancer relapse, and general immunodeficiency, resulting in a patient more susceptible to viral, bacterial, and fungal infection. In a multi-center study, disease-free survival at 3 years was not different between T cell-depleted and T cell-replete transplants. Treatment
Intravenously administered glucocorticoids, such as prednisone, are the standard of care in acute GvHD and chronic GVHD. The use of these glucocorticoids is designed to suppress the T-cell-mediated immune onslaught on the host tissues; however, in high doses, this immune-suppression raises the risk of infections and cancer relapse. Therefore, it is desirable to taper off the post-transplant high-level steroid doses to lower levels, at which point the appearance of mild GVHD may be welcome, especially in HLA mis-matched patients, as it is typically associated with a graft-versus-tumor effect.. Cyclosporine and tacrolimus are calcineurin inhibitors.
Descending perineum syndrome (also known as levator plate sagging) refers to a condition where the perineum "balloons" several centimeters below the bony outlet of the pelvis during strain, although this descent may happen without straining. The syndrome was first described in 1966 by Parks et al. Signs and symptoms
Abnormal descent of the perineum may be asymptomatic, but otherwise the following may feature:

perineodynia (perineal pain) 
Colo-proctological symptoms, e.g. obstructed defecation, dyschesia (constipation), or degrees of fecal incontinence
gynaecological symptoms, e.g. cystocele (prolapse of the bladder into the vagina) and rectocele (prolapse of the rectum into the vagina)
lower urinary tract symptoms, e.g. dysuria (painful urination), dyspareunia (pain during sexual intercourse), urinary incontinence and urgencyOther researchers concluded that abnormal perineal descent did not correlate with constipation or perineal pain, and there are also conflicting reports of the correlation of fecal incontinence with this condition. Cause
One of the main causes is suggested to be excessive and repetitive straining during defecation. Other causes include weakness of the pelvic floor muscles (secondary to age-related neuropathic degeneration or traumatic injury during pregnancy and labor. Diagnosis
Diagnosis is by rectal examination. A specialized tool called a "Perineocaliper" can be used to measure the descent of the perineum. A retro anal ultrasound scan may demonstrate the condition. "Anti sagging tests", whereby the abnormal descent is corrected temporarily, may help to show whether symptoms are due to descending perineum syndrome or are in fact due to another condition. Normally, the anal margin lies just below a line drawn between the coccyx (tailbone) and the pubic symphysis.