I’m a woman and I intend to go and perform my umrah during Ramadhan. The issue is I would often experience white vaginal discharge and I would usually wear a tampon to avoid it when I’m praying. I intended to wear it when I’m performing my tawaf (circumambulation) whilst I’m fasting. My question is, does wearing tampon invalidate my fast if I wear it before performing the tawaf?
Waalaikumussalam wrt, wbt.,
Alhamdulillah, praise and thanks to Allah for the countless blessings He has blessed us all with. Blessings and salutations to the Prophet Muhammad PBUH, his wives, his family, companions and all those that follow his teachings to the day of judgement.
Among the Matters Which Invalidate Fast
Allah SWT states:
وَكُلُوا وَاشْرَبُوا حَتَّىٰ يَتَبَيَّنَ لَكُمُ الْخَيْطُ الْأَبْيَضُ مِنَ الْخَيْطِ الْأَسْوَدِ مِنَ الْفَجْرِ ۖ ثُمَّ أَتِمُّوا الصِّيَامَ إِلَى اللَّيْلِ
“And eat and drink until the white thread of dawn becomes distinct to you from the black thread [of night]. Then complete the fast until the sunset.”
Surah al-Baqarah (187)
It is an obligation for those who are fasting to abstain themselves from matters that invalidate the fast after setting the intention to fast. Among them is intentionally and voluntarily inserting something inside any open body cavity which includes the vagina. Thus, if a person inserted something into the inner part of the vagina which is not the outer part (apparent/visible) when a woman is squatting and not the parts of which are obligated to be washed for purification (minor and major hadas), then her fast is invalid according to madhhab al-Syafie. This, if it is done after the sun has risen and before the sun sets.
However, it is inserted before and taken out after the sun rises, then it does not invalidate fast. Syeikh Nawawi al-BIntani Rahimahullah said: “If a person inserted something into his anus or ear with a type of wooden stick before dawn while he is fasting, then take it out after the sun has risen, it does not invalidate his fast.”
Refer Kasyifah al-Saja (462)
The Usage of Tampon
Here we include the definition of tampon. According to 4th Edition Kamus Dewan, tampon is defined as “a plug of material from linen, wool or others, used to stop a wound or block an opening in the body and absorb blood or secretions.” 
Thus, the ruling of wearing tampon whilst fasting invalidates her fast if it is inserted into any open cavity (vagina). However, if it is done before dawn and it is taken out after the sun rises, then it does not invalidate the fast for the insertion happened before imsak and not while she is fasting.
May Allah SWT grant us goodness and accept our fasts.