IBD and seasonal changes?

I have gone through the forum in search of info on IBD and seasonal changes.  I have a male tabby, Zipper, who will be 11 years old next month.  He was diagnosed with IBD when he was three or four years old. 

If I didn't have a calendar, I would know what month it is by when Zipper's IBD flares up.  He is guaranteed two flare ups per year - one in March and one in November.  So, to me that suggests there is a seasonal component to his IBD.

Has anyone else with IBD kitties noticed a seasonal trend?

He is on a grain free diet - Wellness canned and Taste of the Wild dry food that has venison and salmon as its main ingredients.  He would be on all canned if I was home all day long to feed him.  I must leave out some dry food to keep him and his (unrelated) little sis, Bubble, fed until I get home 12 hours later.  I do not wish to put him on a raw diet, one reason because if it was the food causing his IBD, then he would have it more often than just two times a year.

His vet agrees that there is some kind of seasonal component.  But, from what I have read online, IBD is a difficult disease to "decipher" as to what the actual cause is.

Thanks in advance!

just bumping this up since I see no one has replied. 

The only seasonal connection that I've seen relates to hairballs. Other than that, raw diet helped my crew.

I have never heard/read of a seasonal component to IBD. The timing does seem suggestive, but I would still look for an environmental trigger.

Sometimes I don't think it is possible to know what the trigger is.  Patches would go for months with no diet change and then have a flare.  Added to that he had the vomiting and constipation instead of loose stools and gas.  I had him to three different vets and finally the fourth one put him on a steroid.  That flare was his worst with two different forms of hepatitis and he was on a feeding tube for awhile.  I tried everything in the house including using all natural homemade cleaners.  I even moved, not for that but I did move while this was going on. My other cat has longer hair with the thick undercoat and I was even taking her to a groomer to be shaved to cut down on the hair that Patches was swallowing.  He is easily stressed and I think that may be at least part of it.  I can't remove every bit of stress from an easily stressed cat.

I do agree that it's very difficult to figure out triggers, especially for something like IBD which seems to present differently in each cat. With stress being a trigger for many cats with all kinds of different illnesses, it is impossible to prevent flares sometimes.

Doing some more thinking about this, I wonder if it's possible for seasonal allergies to cause stress in the body which then leads to an IBD flare?

Bumping/commenting because I was searching this point. My IBD cat has been having (maybe?) a flare up this week. He does this gag thing when he's purring, but hasn't actually vomited yet. It's only been goin on for a few days, and he's been eating normally and acting totally normal otherwise.
I'm wondering if it's an actual flare up, or if maybe he has a stubborn hair ball with the changing seasons. The weather has been starting to get consistently warmer, and he's a big fluff ball and is the groomer in my pack of three.
He has been on Hills I/D dry food with a lot of success. As much as I want to make the switch to raw, he is just not having it. I've tried literally every flavor Primal has to offer, and he completely refuses.
I guess I'm just wondering if anyone else has seen a correlation between changing seasons and a flare up?