Question Summary:
Can washing my anus during istinjā or shower break my fast?

Question Detail:

I have a really important question.  I tend to use excessive water during istinjā and shower due to an extreme waswasah problem.  My question is that (because I have read this) water entering into the front and rear private parts via washing during istinjā or shower really breaks the fast.  I feel I can somehow wash the front private part three or four times in a way and still somehow avoid water from going inside my front part, but I am still really unsure about the rear part.  You have written in  one of your answers that if water enters as long as the suppository reaches, the fast would be invalidated.  Can you please tell me how long is a suppository?  Is there any excuse for someone like me?  During shower, I have great doubt that water enter the rear part because I wash it thoroughly and might slightly allow the water to enter in an effort to make sure that it is properly washed.  I draw apart the cheeks to allow water to reach the anus for proper washing.  Please guide me as to what should I do.

Answer :

Assalāmu `alaikum Warahmatullāhi Wabrakatuh,
Washing the anus during istinjā and shower will not break the fast.  As you have correctly identified, your concerns arise from waswasahs, and the cure of waswasahs is to simply ignore them. 
And Allah Ta’āla Knows Best
Mufti Abrar Mirza
Chicago, IL (USA)
Checked and Approved by,
Mufti Ebrahim Desai.
www.daruliftaa.net