Ischemic Colitis: This condition is a strong candidate given the combination of abdominal pain, bloody diarrhea, and the potential for hypotension leading to or exacerbating ischemia. The presence of AKI could be secondary to hypotension or a manifestation of systemic involvement.

Inflammatory Bowel Disease (IBD) Flare: Both Crohn's disease and ulcerative colitis can present with abdominal pain, diarrhea (which may be bloody), and systemic symptoms. Hypotension could be due to severe disease or complications like toxic megacolon, and AKI might result from dehydration or medication side effects.
Severe Gastroenteritis: Certain bacterial or viral infections can cause severe gastroenteritis leading to abdominal pain, bloody diarrhea, and hypotension due to dehydration. AKI could be a consequence of severe dehydration.
Mesenteric Ischemia: Although more commonly associated with acute abdominal pain and possibly diarrhea, mesenteric ischemia can lead to bloody stools if there's infarction of the bowel. Hypotension and AKI could be part of the clinical picture due to systemic response and decreased perfusion.

Bleeding Disorder or Coagulopathy: Conditions like hemophilia or acquired coagulopathy could lead to gastrointestinal bleeding, presenting as bloody diarrhea. Hypotension could result from significant blood loss, and AKI might follow due to hypoperfusion or contrast-induced nephropathy during diagnostic imaging.
Sepsis: Any infection leading to sepsis could present with abdominal pain, diarrhea, hypotension, and AKI. The bloody nature of the diarrhea might not be as common but could occur depending on the source of the infection.
Abdominal Aortic Aneurysm (AAA) or Dissection: Although less common, an AAA or dissection could cause abdominal pain and hypotension. If the bowel is involved (e.g., due to embolization), bloody diarrhea could occur, and AKI might result from renal artery involvement or hypoperfusion.

Thrombotic Thrombocytopenic Purpura (TTP): A rare disorder characterized by thrombocytopenia, microangiopathic hemolytic anemia, renal failure, neurological symptoms, and fever. Gastrointestinal symptoms like abdominal pain and bloody diarrhea can occur, and AKI is a known complication.
Hemolytic Uremic Syndrome (HUS): Typically presents with the triad of hemolytic anemia, acute kidney injury, and thrombocytopenia. It can be preceded by a diarrheal illness, and abdominal pain is common. Bloody diarrhea might be seen in the prodromal phase.
Vasculitis: Certain types of vasculitis, like Henoch-Schönlein purpura or systemic vasculitides (e.g., ANCA-associated vasculitis), can present with abdominal pain, gastrointestinal bleeding, renal involvement, and hypotension due to systemic inflammation.