I think this is actually just a complication of a Meckel's Diverticulum - Acute Meckel's Diverticulitis - which would be consistent with his presentation of acute abdomen + tarry black stools + CT/gross findings. It can be described as a mimic of appendicitis (as seen here).

I think if they wanted us to think this was Crohn's + Meckel they would have given us a more classical Crohn's presentation (skip lesions, insidious onset, non bloody stool)

As per page 378 in FA 2019, this appears to be a classic presentation for Meckels.

-They say its a bulge (I usually associate that with some type of diverticulum)

-"May contain ectopic acid secreting gastric mucosa and/or pancreatic tissue". This is consistent with the inflamed small bowel

-Can cause hematochezia/melena and RLQ abd pain

-Can cause obstruction near the terminal ileum

I originally got this question wrong because for some reason I just associated the fat stranding with Crohns and was just kind of thrown off. Overthinking can really lead to your detriment. Be kind to yourself and know that even if you dont outright know it, your subconscious definitely knows it haha

Good luck everyone!

I was thinking Crohns with the multiple episodes over the last year, fat stranding, terminal ileum involvement which would then maybe be describing a false diverticulum involving the mucosa.

I think this is a Meckel diverticulum presentation!

"Ileal (Meckel) diverticulum occurs when a remnant of the vitelline duct persists, thereby forming a blind pouch on the antimesenteric border of the ileum. It is often asymptomatic but can become inflamed if it contains ectopic gastric, pancreatic, or endometrial tissue, which may produce ulceration. It is typically found 2 feet from the ileocecal junction, are 2 inches long, and appears in 2% of the population."

Kaplan 2020 Book.

Antimesenteric seems to be a buzzword for Meckels, saw this in UWorld as well (might have been one of the UWSA).