Does the fluid that is discharged from a man upon touching or caressing his wife nullify ablution (wudu') or necessitate a ritual bath (ghusl), knowing that frequent bathing causes him back pain due to rheumatism?

The fluid that is discharged during foreplay is often pre-seminal fluid (madhy), and it does not necessitate ghusl (ritual bath). Rather, it necessitates purifying whatever it has touched on the body and clothes, and performing wudu (ablution) for prayer. However, if semen (manyi) is discharged due to foreplay, then ghusl is obligatory.