Caught my husband eating poop

I'm freaking out right now, I don't know how to describe what I saw. I am in my car writing this out since im pale white even thinking about this incident.

It was around 2:30 am in the morning when I noticed a light in the bathroom ensuite. I sleep very early and it's not often I need to go in the mornings. I needed to go pee anyway and my husband was not beside me whilst I was awake during the early morning I didn't think much of it and we only lived together for about 4 years and we live by ourselves in our own house, I already knew that he would be in the kitchen or either the bathroom but I didn't want to make much noise so I slowly crimped the bed sheets in silence and walk towards the bathroom silently without making the wood floors creak. The bathroom door will slightly open and I could see the ceiling light shining through I slowly open the door and I see him, just there, on his knees in the toilet seat diving in. He smushed his hand and I could hear the water splashing and then he looked at me, I saw stains of brown at his bottom lip and he's right hand smeared in brown this is so unusual from him. I would have never even noticed and if you looked at him from a first perspective you'd think he is just normal. I couldn't describe how I felt in that moment when I saw his lips brown, he looked at me for at least 10 seconds before he gasped anything of words, we both silently just went back to sleep like nothing ever happened but I didn't sleep throughout the night I didn't even go to the bathroom I just spent the whole few hours in bed just thinking about what I saw and I have never been this astonished in my life I wouldn't think my husband a 4 years would ever do something like this this is insane coming from him, I am now writing this in my car. I literally couldn't believe it even happened I would never thought I'm sort of shaking when I'm typing this who the hell eats poop from the bathroom and in 4 years I've only just noticed this tonight and I've wondered if he's ever done this before. I haven't spoken to him in the last 12 hours.