Differential Diagnosis for Right Lower Back Pain, Right Lower Abdominal Pain, and Right Rectal Pain or Fullness
Single Most Likely Diagnosis
- Appendicitis: The combination of right lower back pain, right lower abdominal pain, and right rectal pain or fullness, especially with a sensation of needing to defecate, is highly suggestive of appendicitis. The pain often starts near the navel and then moves to the right lower abdomen. The sensation of needing to defecate can occur due to the appendix's location near the rectum.
Other Likely Diagnoses
- Diverticulitis: Inflammation of a diverticulum in the colon can cause severe pain, usually on the left side but can occur on the right, especially if the sigmoid colon is involved. Symptoms can include lower abdominal pain, changes in bowel habits, and possible rectal bleeding.
- Kidney Stones (Nephrolithiasis): Stones in the right ureter can cause severe pain (renal colic) that starts in the flank and radiates to the groin. The pain can also be felt in the lower abdomen and can cause a sensation of needing to urinate.
- Prostatitis: Inflammation of the prostate gland can cause pain in the lower back, abdomen, and rectal area, along with urinary symptoms like frequency, urgency, and pain while urinating.
Do Not Miss Diagnoses
- Ectopic Pregnancy: Although less common, an ectopic pregnancy can present with lower abdominal pain and can be life-threatening if not promptly diagnosed and treated. The pain can be on one side and may be accompanied by vaginal bleeding and a missed period.
- Intestinal Obstruction: A blockage in the intestine can cause severe abdominal pain, vomiting, and constipation. The pain can be localized to one area, depending on the site of obstruction.
- Ruptured Aortic Aneurysm: A tear in the aorta can cause sudden, severe back pain that radiates to the abdomen, and it is a medical emergency.
Rare Diagnoses
- Carcinoid Tumor: A rare tumor of the neuroendocrine system that can cause abdominal pain, diarrhea, flushing, and wheezing. It is often found in the appendix but can occur in other parts of the intestines.
- Endometriosis: A condition where tissue similar to the lining inside the uterus grows outside of it, causing pain, especially during menstruation. It can cause chronic pelvic pain, heavy bleeding, and infertility.
- Pudendal Neuralgia: A condition characterized by pain in the distribution area of the pudendal nerve, which can include the rectal area, causing a sensation of needing to defecate, along with pain during sitting or sexual activity.