Question Summary:
Does one have to wash anus only or the part between the testicals and anus as well after Istinja?

Question Detail:

Assalam o Alaikum.
I want to ask that after defecating i.e passing stools does one have to wash anus only or the part between the testicals and anus as well ?
 If washing anus only is necessary  , is  the water from anus after purification is pak ? Because in the processes of washing water does not always remains on the same spot i.e it flows . Please tell me the answer I spend really long in the toilet for washing anus and after that the middle portion between testicles and anus three times. 
In case of using a vessel (Traditionally called lota ) for purification does it still needs to be washed 3 times or just removing the impurity will be enough ? 
jazakAllah

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
 
1.The purpose of purification is to remove the impurities.
If the faeces [impurity] did not spread beyond the anus, then the washing of the anus will be sufficient.
2. In principle, the water that washes away the filth is filthy. The water after that is pure [paak].
Thus in the enquired situation the water flowing to other parts of body will be pure. [Your concern arise from wasawis, simply ignore them]
3. If you are sure that by washing three times impurity will be removed, then it will suffice regardless of using “lota”, spray or jug.  [1] [2] [3] [4] [5]
 
And Allah Ta’āla Knows Best
Anas Sharieff Qasmi.
Student Darul Iftaa
Hyderabad, India.
Checked and Approved by,
Mufti Ebrahim Desai.
 
 [1] ثم الاستنجاء بالأحجار إنما يجوز إذا اقتصرت النجاسة على موضع الحدث[ الفتاوى الهندية ١/٤٨]
 [2] اگر نجاست سے مخلوط ہوکر چھینٹیں دوسرے عضو پر جائیں تو اس کو بھی پاک کرنا ہوگا ورنہ نہیں٢٣٨/٥ فتاویٰ محمودیہ
 [3] ويستعمل الماء إلى أن يقع في غالب ظنه أنه قد طهر [الهداية ١/٧٥] 
ولا يقدر بالمرات إلا إذا كان موسوسا فيقدر بالثلاث في حقه وقيل بالسبع[الهدايه ١/٧٥]
 
 [4] وقال: يغسل إلى أن يقع في قلبه أنه طهر [تاتارخانيه:١/٢١٥]
 [5] ولا يقدر بالعدد إلا أن يكون موسوسا فيقدر في حقه بالثلاث [الفتاوى الهندية:١/٤٩]