Differential Diagnosis
- Single most likely diagnosis
- Ovarian cyst or torsion: The patient's description of the pain as similar to ovulation pain but persistent and severe, along with its location in the left lower quadrant, suggests a possible ovarian pathology. The fact that she is ovulating and the pain is sharp also supports this diagnosis.
- Other Likely diagnoses
- Diverticulitis: Although the patient reports normal bowel movements, diverticulitis can cause severe left lower quadrant pain and is more common in individuals with a low-fiber diet, which might be a concern for a vegan if the diet is not well-planned.
- Constipation: Despite the patient's report of normal bowel movements, constipation can sometimes present with severe pain, especially if there is a significant buildup of stool. However, the sharp nature of the pain and lack of relief after bowel movements make this less likely.
- Irritable Bowel Syndrome (IBS): IBS can cause abdominal pain and alterations in bowel habits, but the sharp, constant nature of the pain described is less typical for IBS.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Ectopic pregnancy: Although the patient reports ovulating and there's no mention of missed periods or pregnancy suspicion, ectopic pregnancy is a life-threatening condition that must be ruled out in any female of childbearing age presenting with severe abdominal pain.
- Appendicitis: While the pain is in the left lower quadrant, which is less typical for appendicitis, it's crucial to consider appendicitis due to its potential for severe complications if not promptly treated.
- Ovarian tumor: Although less common, ovarian tumors can cause persistent pain and should be considered, especially if the pain does not resolve.
- Rare diagnoses
- Endometriosis: While endometriosis can cause chronic pelvic pain, the acute onset of severe left lower quadrant pain is less typical for this condition.
- Inflammatory bowel disease (Crohn's disease or ulcerative colitis): These conditions can cause abdominal pain and changes in bowel habits, but the presentation would typically include other symptoms such as diarrhea, weight loss, or blood in the stool.
Given the acute onset of severe pain, it would be prudent for the patient to seek immediate medical attention to rule out life-threatening conditions.