Are Bibia permitted to do Guru Sahib di Seva (or at least read Gurbani from Guru Granth Sahib) while menstruating?

Some people say "no" to this question and although I understand that we should all be physically clean, this matter is different from just being unclean in itself as menstruating is a natural process that can't be controlled unlike other bodily functions. If you're generally unclean, then that is a choice which you can rectify with a quick shower - not the same with menstruating, which is not a choice and can't be controlled for a week every month.

To suggest that women are not allowed to do Guru Sahib di Seva for a whole week every month doesn't seem to be in-line with several themes of Guru Sahib's message, such as: (1) we're all meant to connect with Guru Sahib and Gurbani every day; (2) the fact that real uncleanliness is in the mind, not on the body; (3) men and women are equal (one soul) and the spiritual opportunities should therefore also be the same.

It doesn't make much sense to penalise women every month for the best part of their lives, for something which isn't their fault, but rather a natural process which is required in order to give birth.

Is this aversion to women during their menstrual cycle something which is more cultural than religious? Muslims believe the same about women.

What is the specific reason for this in some Sikh minds? Are there any Gurbani quotes and other references which support any particular views?

The idea is only that the person sitting at taabiya not soil the taabiya in any way. That can mean either through blood or other bodily fluids. If someone has a wound that will soak through, then they too should avoid sitting at taabiya. Similarly someone with an uncontrolled bladder issue.

That having been said, if one can be sure that controls are in place to ensure taabiya will not be soiled then that is fine. The idea is not that a woman in her period is inherently dirty or has a dirty aura or something. It's just the practical issue of making sure taabiya is kept absolutely clean.

One of the criteria’s for doing Guru Sahib dee Seva is that your cloths (including Kachera) should be clean. Bibia during menstruating out of satkar for Guru Jee feel that it might not be practical to follow the rule so they normally avoid doing seva.

It is not a case of being banned to do seva or being impure it’s just the practicality of it.

Most women feel a slight weakness/tiredness within them during this period because of the imbalance brought about by the loss of blood so they themselves usually don’t want to do anything demanding or sitting for long periods.

It would only be real discrimination if women were not allowed to do Guru Jee’s Seva at all. This is only something for a few days.