Differential Diagnosis

The patient's symptoms of alternating constipation and diarrhea, diffuse abdominal pain, and tenderness to palpation in the LLQ of the abdomen can be attributed to several possible diagnoses. Here's a categorized list of potential diagnoses:

• Single most likely diagnosis

  • C. Irritable bowel syndrome (IBS): The patient's symptoms of alternating constipation and diarrhea, abdominal pain, and sensitivity to certain foods are consistent with IBS. The absence of other alarming symptoms such as weight loss, fever, or bloody stools also supports this diagnosis.

• Other Likely diagnoses

  • B. Crohn’s disease: Although the patient has celiac disease, which increases her risk for other autoimmune disorders, the lack of systemic symptoms such as weight loss, fever, or bloody stools makes Crohn's disease less likely. However, it's still a possibility, especially given her history of abdominal surgery and celiac disease.
  • D. Diverticulitis: The patient's tenderness to palpation in the LLQ of the abdomen could suggest diverticulitis, but the absence of fever, nausea, or vomiting makes this diagnosis less likely.

• Do Not Miss

  • A. Bowel obstruction: Although the patient's symptoms do not strongly suggest a bowel obstruction, it's essential to consider this diagnosis due to her history of appendectomy, which increases her risk for adhesions and potential bowel obstruction. The presence of abdominal pain and altered bowel habits warrants careful evaluation to rule out this potentially life-threatening condition.
  • Other conditions: Other "do not miss" diagnoses include intestinal ischemia, inflammatory bowel disease (IBD) flare, or celiac disease complications, although these are less likely given the patient's presentation.

• Rare diagnoses

  • Microscopic colitis: This condition can cause chronic diarrhea and abdominal pain, but it's less common and typically affects older adults.
  • Gastrointestinal motility disorders: Conditions like gastroparesis or intestinal pseudo-obstruction can cause altered bowel habits and abdominal pain, but these are relatively rare and often associated with other systemic symptoms.
  • Other rare conditions: Other rare diagnoses, such as carcinoid syndrome or VIPoma, are unlikely given the patient's presentation and lack of systemic symptoms.