At a loss

Quick synopsis... Had my gallbladder out a couple years back and have had nothing but problems since it's removal. I have been DX'd with IBS-D, which seems to have lightened up a little over the past few months, but every now and then, doesn't matter which foods i eat, i'll have a day or two where I bleed a bit during/after the bowel movement. TP will have some blood on it, and the water will be pink to red. It may last a couple of times and then stop, or it may last a couple days then stop. I might go weeks without bleeding once and then boom, it hits for however long it lasts.. a couple movements or a couple days. It isn't dark red, so i am assuming it is probably an anal fissure that gets torn (even though I never have to strain for a movement), or it's a little hemorrhoid (which i was checked for previously but none were found). I have had a colonoscopy right before my gallbladder surgery a couple of years ago, along with ct scans, ultrasounds, etc. Also had them check it the first time i had blood and they did that wonderful finger in the great unknown and said they didnt feel anything. SO i am kinda worried a bit about the bleeding.. though it doesn't usually last longer than a day and it's not a HUGE amount, it's still a bit worrisome. I haven't been able to find what the trigger is if it's food.. I eat all sorts of stuff.. what i ate last night i've had many times before without ever having any blood.. so... any ideas?

The IBS part of it doesn't bother me.. i mean it does, but it's more a nuisance than anything else.. it's the blood in the stool at random periods that has me freaked out a little.. i could eat the same stuff today, eat the same exact stuff tomorrow.. and one day i will be fine, the next day, i might bleed.. it just hasn't made any sense to me.