talmud gemara - How did Rambam eliminate "ben gilo" from the halacha?

The gemara in Elu Metzios (Bava Metzia 30b) says:

אמר מר (אשר) ילכו - זה ביקור חולים. היינו גמילות חסדים! לא נצרכה אלא לבן גילו ,דאמר מר בן גילו נוטל אחד מששים בחליו ,ואפי' הכי מבעי ליה למיזל לגביה

My chavrusa and I found that interesting because until we read this gemara, we had thought that the drasha on visiting the sick was that you take away 1/60 of the sick person's illness. Turns out that this is not only a double-edged sword (i.e. the 1/60 illness doesn't just go away, but sticks to the visitor instead!) but also this only applies to someone of the same mazal ("ben gilo") as the choleh!

So we checked out the halacha in the Rambam. Here's what he has to say (Hilchos Avel 14:6):

וכל המבקר את החולה, כאילו נטל חלק מחולייו, והקל מעליו

Hello? What happened to "ben gilo"? Is this Rambam's rationalist way of seeing things, that he summarily changed the pshat from the gemara? The Shulchan Aruch likewise rules like the Rambam, that this healing effect of bikkur cholim applies to everyone. And I haven't found anyone (though my research has been far from exhaustive) who disagrees, or mentions a word about "ben gilo" in the halacha!

So how did this concept from the gemara get struck from the record when it came to halacha?

Answer

You're not mistaken: in fact the Tur and Shulkhan Arukh (335:2) say that only a בן גילו has the ability to take some of the sickness with him. This difficulty was recognised by the Drisha on Ramba"m and he stresses Ramba"m's wording: כאילו נטל חלק מחולייו - it is as if he takes part of the illness. However, there's a note in my Ramba"m that directed me to Midrash Rabbah Vayikra 34:1.

R' Huna says: [Tehilim 41:2] talks about someone who visits an invalid. As R' Huna says, everyone who visits a sick person removes one sixtieth of the invalid's illness. They challenged R' Huna : if so, why not have sixty people visit the invalid, then he can go shopping with them (i.e., then the invalid will be well again)? [R' Huna] replied, sixty - but only if they love him as they love themselves. Still, it will make him feel better.

So it seems to me that Ramba"m was aware that the Gemara restricts the healing power of visitors to a בן גילו, but he chose to emphasise the fact that all visitors make the invalid feel better, and he followed R' Huna in the Midrash by tying it to the mystical idea of the בן גילו.