Answered by: Maulana Mohammed Dilwar Hussain
I have been suffering from constipation for a number of years. When relieving myself I often have to insert my fingers in my anal passage to help relieve myself. Does this nullify the fast? I have been doing this for years and I’m unaware of how many years this has been ongoing. Do I have to make qadha. This would mean years of qadha?
In the name of Allah, the Most Gracious, the Most Merciful
If a dry finger is inserted and then removed, the fast will not break.
If after the dry finger was inserted, it was removed and then re-inserted, the fast will break and a Qadhaa of that fast will have to be kept.
If the moist finger was inserted slightly, the fast will not break. However, if the moist finger reached the place where the enema is inserted, the fast will break.
This is the ruling, whether done knowingly or unknowingly.
The general rule is, in the state of fasting, if water enters the anal passage (through inserting one’s moist finger) and the water reaches the point where the enema is inserted then the fast will break. This point is approximately five to six inches. If water does not reach this point, the fast will not break. [Radd ul Muhtaar; volume 2, page 397] 
You will need to ponder and work out if at any time your fingers surpassed this point. If they did, then you will need to do Qadha of those fasts.
Only Allah knows best.
Written by Maulana Mohammed Dilwar Hussain
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham
قال في الدر المختار ولو بالغ في الاستنجاء حتى بلغ موضع الحقنة فسد و هذا قلما يكون ولو كان فيورث داء عظيما قال الشامي ثم في بعض النسخ المحقنة بالميم و هي أولى قال في الفتح و الحد الذي يتعلق بالوصول إليه الفساد قدر المحقنة