Differential Diagnosis for LLQ Pain
Single most likely diagnosis
- Diverticulitis: This is a common cause of left lower quadrant (LLQ) pain, especially in older adults. The absence of rebound tenderness and guarding suggests a mild or early case, which is consistent with diverticulitis.
Other Likely diagnoses
- Constipation: Constipation can cause LLQ pain due to the location of the descending colon. The lack of rebound tenderness and guarding makes an inflammatory or infectious cause less likely, increasing the likelihood of a functional cause like constipation.
- Irritable Bowel Syndrome (IBS): IBS can cause chronic or recurrent abdominal pain, including LLQ pain, without signs of peritonitis like rebound tenderness or guarding.
- Ovarian cyst or torsion (in females): While ovarian pathology can cause severe pain, the absence of rebound tenderness and guarding might suggest a less severe condition like an ovarian cyst rather than torsion.
Do Not Miss diagnoses
- Ectopic pregnancy (in females of childbearing age): Although the pain might not be severe enough to cause rebound tenderness or guarding, ectopic pregnancy is a life-threatening condition that must be considered in any female of childbearing age with LLQ pain.
- Appendicitis with atypical presentation: While appendicitis typically presents with right lower quadrant pain, an atypical presentation with LLQ pain can occur, especially if the appendix is retrocecal. The absence of rebound tenderness and guarding does not rule out appendicitis entirely.
- Intestinal obstruction: Early intestinal obstruction might not cause significant peritoneal signs like rebound tenderness or guarding but can lead to severe complications if not addressed promptly.
Rare diagnoses
- Inflammatory bowel disease (e.g., Crohn's disease, ulcerative colitis): These conditions can cause chronic inflammation and pain in the LLQ but are less common than other causes.
- Colonic neoplasm: Although rare, a colonic tumor could cause LLQ pain, especially if it involves the sigmoid colon.
- Endometriosis (in females): Endometriosis can cause cyclic pain, including LLQ pain, due to endometrial implants in the pelvic region.