Differential Diagnosis
- Single most likely diagnosis
- Inflammatory bowel disease (IBD), specifically ulcerative colitis: The patient's symptoms of loose, bloody stools, intermittent lower abdominal pain, and urgency to use the bathroom are consistent with IBD. The history of intermittent bloody stools two years ago that resolved without medication also supports this diagnosis, as IBD can have a relapsing-remitting course.
- Other Likely diagnoses
- Irritable bowel syndrome (IBS): Although IBS typically does not cause bloody stools, the patient's symptoms of abdominal pain, changes in bowel habits, and straining during bowel movements could be consistent with IBS. However, the presence of bloody stools makes IBD more likely.
- Pregnancy-related bowel changes: Pregnancy can cause changes in bowel habits, including constipation or diarrhea, due to hormonal changes and pressure from the expanding uterus. However, the presence of bloody stools and abdominal pain makes this diagnosis less likely.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Intestinal ischemia: Although rare, intestinal ischemia can occur during pregnancy due to compression of the mesenteric vessels by the expanding uterus. The patient's symptoms of abdominal pain and bloody stools could be consistent with intestinal ischemia, which is a medical emergency.
- Colon cancer: Although rare in young women, colon cancer can cause symptoms of bloody stools, abdominal pain, and changes in bowel habits. A family history of colon cancer or other risk factors would increase the likelihood of this diagnosis.
- Rare diagnoses
- Infectious colitis: The patient's symptoms could be consistent with an infectious cause, such as Clostridioides difficile or Salmonella. However, the absence of fever, vomiting, or other systemic symptoms makes this diagnosis less likely.
- Radiation colitis: If the patient had a history of radiation therapy to the abdomen, radiation colitis could be a possible diagnosis. However, there is no mention of such a history in the patient's presentation.