I have posted quite a lot on this topic, since my resection in 2022.
Without going back through past info as seen here, this is what I believe it all comes down to.
Improperly Assumed Expectations.
IAE is through no fault of your own. Doctors will have you believe that side effects will go away in a couple of weeks, and you can find online that it could likely be 2 months.
Not true.
No one has ever had lightning recovery from Colon resection.
And diarrhea is not just a side effect, it is a known product of Colon resection surgery.
My belief has been that the closer the resection to your rectum, the more severe diarrhea becomes.
And a Sigmoid Colon resection is like guaranteed long term diarrhea.
I don't think that doctors will tell you that. Because everyone and every case can be unique, I think that talking about or predicting side effects is seen as an area best skirted over.
Everyone leaves the hospital with unanswered questions, some vague understandings, and unreasonable expectations of recovery.
It's just the way it it.
I was told 2 months of diarrhea, never really believed that because my diarrhea was extreme and explosive.
You ever feel like something undesirable is not going away any time soon? That was always me and my severe diarrhea lasted a complete year almost to the day, and abruptly went away like turning off a switch!

While none of this might be helpful to you, it just might relieve some improperly assumed expectations and you can better settle in for the ride.
You will make it through fine!
We all do!
PAUL
P.S Three months and having "periodic" diarrhea!?
That's the best kind! Most of us have "daily-all-day" diarrhea; never periodic!