Intense horror is referred to as "looming/impending fears of doom/dread" in medicine.. could be worth you checking out kidneys/adrenals (there’s a rare benign tumour that can grow on our adrenals called pheochromocytoma - that legit functions as a provider of intense horror kidding aside it can either over or under produce certain hormones mainly the ones that control fight or flight if I remember correctly so cortisol and epinephrine which is adrenaline’s new name). Again, it’s super rare BUT could be worth investigating if your IBS is actually something related to your endocrine system, so hormonal / pituitary-related.

Edit: removed a double word

pheo crisis would have BP and pulse through the roof as well (and probably lots of other things, flushing, HR, respiration, etc), and the first thing done in ER triage is vitals.

It can be potentially an allergy also, also can induce impending doom, and BP variation could be within the norm, and even sometimes hypertensive instead of hypotension.

endocrine-related IBS? how so?

What you shared is quite interesting. But looming/impending fears of doom/dread is one of the tell-tale symptoms of anxiety (which is more plausible than a rare ailment for how common anxiety is. Anxiety also often has physical symptoms).

I have Crohn's disease and I get extremely sharp depressive symptoms up to a week before a flare up. The longer the lead time the worse the flare up. It's rather interesting to have depression re-framed as a symptom rather than as a disease. It does make me wonder if in the future we'll be looking at the treatment of depression today like we do at the treatment of fever with leaches.

It's likely the inflammation that's causing the depression rather than any particular molecule produced by a bacterium though. I have the same experience with UC to the extent that taking steroids causes almost immediate relief of the depressive symptoms and I relapse when I taper. In my last flare, I tried to track depressive symptoms against CRP levels in my blood but being depressed, lost interest... Joking aside, I also wasn't getting the blood tests with sufficient frequency for it to be useful. "The Inflamed Mind" by Edward Bullamore is a good read on the subject.

How can you be sure the steroids themselves aren't causing the mood change? I also have UC and steroids make me noticeably, behaviorally manic. I don't think the mania is due to the absence of inflammation.

I can't. But there's good evidence that inflammation is linked with depression and steroids unquestionably reduce inflammation. They may well have further effects. They are certainly not something I want to take consistently.

Same disease and same effect, Mood is often a bellweather of a flare up.

I don't have IBS, but I have noticed that I feel a strong, deep sense of anxiety when my pipes are backed up, and it instantly goes away when I go number 2.

If you’re backed up sort of often you should beware of diverticulitis. It occurs in younger and younger people today. It’s not too strange to see a person in their early 30’s having a partial colectomy (or worse) nowadays.

let me guess too much meat or fast food?

Generally a lack of fiber.

> the only times I have ever had dark moods in my adult live was during IBS episodes.

You've had a very happy life!

I have this as well. The gloom and doom kicks in about a day or two before the symptoms do. I take a strict regimen of fiber and probiotics to keep it at bay.

What fiber do you use, I should try adding it to my menu, probiotics help me a lot.

PHGG, GOS and lactulose (if you don't have SIBO) are relatively good prebiotics in my experience. However, the type of prebiotics you use should be tied to what's going on in your microbiome. Some common ones, such as Inulin, can feed both good and bad bacteria (and good bacteria become bad if they overgrow).

Psyllium husk (Metamucil is the most common brand name) is the most impactful for me.

this might also be as simple as "feeling bloated and blocked up makes you feel like shit"

Also the reverse (brain->gut). Obvious to anyone who suffers from motion sickness.

you ever had a colonoscopy biopsy? have them stain it for CD117, see if mast cells are outside the normal range of density.

Pretty sure react mentally to any physical sensation in your body.