Perplexed by IBD Kitties Behavior

I have three kittens same litter, One has IBD.  He's always been different from the other two, who are lap cats and very easy to pet and pick up.   He's not aloof, but he's one of those cats that both is begging you to pet him and then suddenly turns around and screams and bats at you - usually with his claws in, but no always.

You can sit and talk to him when he's up on something and he purrs and rolls over and purrs - it's like petting a ticking time bomb though so I stick to the verbal stroking.  When company comes he'll stand there purring and being charming, but if the raise a hand to  pet him, he'll hiss.   He's only one who'll his at the vet, but he's all talk, at least so far. 

So anyway tonight he jumps up an hour after dinner and plants himself firmly in front of me rolling and gyrating and purring like he's having a love fit.  He got a few good love bites in when I was trying to pet him.  This went  on for a good two minutes.  It's just felt -  well - bizarre.  Now he's just hanging out in his cat bed and purring up a storm.

Is there some sort of developmental stage thing when cats get to be his age - his almost two y.o.?  My impression has always been he's at the bottom of the totem pole around here; his sister is half his size and she body slams him regularly, or used to.  I don't get the feeling he's quite as passive as he used to be. 

My impression is that this does not actually seem related to his IBD, but instead just to his personality- plenty of cats without IBD act similarly to him!

A good article for you to check out is this one (scroll down a bit to aggression triggered by petting): http://www.thecatsite.com/a/cat-aggression-toward-people

What I suspect is happening is something that is discussed in the article- your cat is biting when he becomes overly stimulated from the petting.  Over time, by observing your cat carefully, you should be able to learn the warning signs that he has reached his limit and stop petting him well before that.

As for hissing at the vet and guests, this is 100% normal.  There is nothing wrong with it or that you need to do about it.  He is telling them hey,back off, I don't know you.

I had a cat with IBD and other digestive issues and he was high maintenance from the get-go even before his diagnosis. I do not believe there is a correlation between IBD and "bad" behavior. I imagine IF the cat is in some sort of pain, then yes, he would lash out or become crabby. OR if the cat is consistently uncomfortable, then I think the cat would be more sensitive to touch and feeling lousy. Certainly, innate personality traits and behaviors are individual and don't have a relation to any disease or diagnosis. Again, I think pain can exasperate and irritate a cat that is already a bit cranky to begin with. In your case, I just think your kitty gets overstimulated easily and in answer to your question about age and maturity. Two years is when some people will notice a change in their cats behavior especially in multiple cat homes. They are fully maturing and social dynamics can change a bit.

Thank you for the replies, he's so funny - today I had an estimator come for some work I want done and he loved her.  He even licked her hand.  Go figure.

He's never really tried to hurt me, but sometimes I feel I'm pushing my luck.  I will pick him up and carry him  around just as an exercise in managing his emotions.  We walk around the house until he stops growling and whining and relaxes.   My theory is that if he associates producing a feeling of safety with getting his shorts in a knot that'll be his coping mechanism.

Some respond well to gradual increased "stimuli" of holding or keeping a hand on them while resting next to or on laps. Some develop more ingrained aberrant behavior in response to "flooding" them with too much stimuli that induces their anxiety/fear or aggression, locking in more "triggers" and volatile responses to stress or environmental changes.

If truly "love bites" that are barely a pinch of the skin, often slow movement in which they head-butt and stroke all over the hand and arm too, I don't worry, but if grabbing skin fast and hard as a warning bite, that is communicating "stop it, or else" which is usually after multiple other attempts with the other cat or human, such as tail-flicking, low vocalizing, or trying to leave the situation.

As mentioned, 2 or 3 years old is a common juncture at which they "find their mature self" and finish developing their personality. Inter-cat relations and human interactions "cement" or set more into their behavior.