Dear Rabbi Simon,
My wife Sarah is both a full time mother and facing medical challenges at the moment. This leaves her very tired and emotionally drained by the end of the day. She also has a phobia of going under water. Consequently, she finds the monthly mikva trip very difficult, and this month impossible to carry out (following numerous medical procedures). I find that this puts a strain on the marriage, which I know is the exact opposite to what this mitzvah is all about. After the seven clean day count, is full immersion always obligatory or can it be relaxed in some way for this type of situation? I look forward to hearing from you soon,
I am sorry to hear of the complicated situation you describe. The difficulty Sarah experiences with immersion in water is unfortunate; I wonder if some form of counseling or therapy could help. The reason I put forward this suggestion (which I recognize has doubtless occurred to you already) is that a woman cannot become tehora following her monthly period without complete immersion in the mikveh. Anything less leaves her in a state in which she is unable to resume normal physical relations within the context of marriage.
Therefore, I would say that immersion per se is not obligatory after the seven clean days (although it is a mitzvah, and is doubtless to be encouraged). However, normal marital relationships cannot be carried out in any way without it.
I hope that Sarah’s health improves and that the situation you describe finds a favorable resolution soon.
There are also a number of mikveh attendants who are trained to help women who have an aversion to immersion. I can give you details if you like.