Neutropenic Colitis (Typhlitis): This condition is characterized by inflammation of the cecum and is most commonly seen in patients with neutropenia, often due to chemotherapy. The clinical presentation typically includes right lower quadrant abdominal pain, fever, and diarrhea, making it the most likely diagnosis given the term "tyriiditis," which seems to be a typographical error for "typhlitis."

Appendicitis: Although the term "typhlitis" suggests involvement of the cecum, appendicitis could present similarly with right lower quadrant pain and should be considered, especially if the diagnosis of typhlitis is not clear-cut.
Diverticulitis: Inflammation of a diverticulum in the colon can cause severe abdominal pain, fever, and changes in bowel habits, making it a plausible alternative diagnosis.
Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease or ulcerative colitis can cause chronic inflammation of the gastrointestinal tract, leading to symptoms that might overlap with typhlitis.

Perforated Viscus: A hole in the wall of the intestine can lead to peritonitis, a life-threatening condition requiring immediate surgical intervention. The symptoms can initially mimic those of typhlitis but would rapidly escalate.
Ischemic Colitis: Reduced blood flow to the colon can cause sudden onset of abdominal pain, bleeding, and potentially life-threatening complications if not promptly addressed.
Intestinal Obstruction: Blockage of the intestine can cause severe abdominal pain, vomiting, and constipation, and if not treated, can lead to ischemia and perforation.

Eosinophilic Gastroenteritis: A rare condition characterized by eosinophilic infiltration of the gastrointestinal tract, which can cause a wide range of symptoms including abdominal pain and gastrointestinal bleeding.
Intestinal Lymphoma: A type of cancer that can cause abdominal pain, weight loss, and changes in bowel habits, though it is much less common than other causes of gastrointestinal symptoms.
Yersiniosis: An infectious disease caused by Yersinia bacteria, which can lead to symptoms similar to appendicitis or typhlitis, particularly in children and young adults.