Differential Diagnosis for Rectal Pain During Bowel Movements

When considering the symptoms of rectal pain during bowel movements, including those with diarrhea, several potential diagnoses come to mind. These can be categorized based on their likelihood and the urgency of diagnosis.

• Single Most Likely Diagnosis

  • Anal Fissure: This is a tear in the lining of the anus, which can cause severe pain during and after bowel movements. The pain is often described as sharp and can be exacerbated by hard stools, but it can also occur with diarrhea due to the irritation and inflammation of the fissure.

• Other Likely Diagnoses

  • Hemorrhoids: These can cause discomfort and pain, especially if they are thrombosed. The pain can be internal (inside the rectum) or external (around the anus), depending on the location of the hemorrhoids.
  • Proctitis: Inflammation of the rectum can cause pain, especially during bowel movements. This can be due to infections, inflammatory bowel disease (IBD), or other causes.
  • Rectal Ulcer: A sore or ulcer in the rectum can cause pain during bowel movements.

• Do Not Miss Diagnoses

  • Rectal Cancer: Although less common, rectal cancer can present with pain during bowel movements, among other symptoms like changes in bowel habits and bleeding. Early detection is crucial for effective treatment.
  • Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis can cause chronic inflammation and ulcers in the digestive tract, leading to pain during bowel movements.
  • Infectious Proctitis: Certain infections, including those caused by sexually transmitted infections (STIs) like gonorrhea, chlamydia, and herpes, can cause rectal pain and inflammation.

• Rare Diagnoses

  • Solitary Rectal Ulcer Syndrome (SRUS): A condition characterized by ulcers in the rectum, often associated with chronic constipation and straining during bowel movements.
  • Rectal Endometriosis: A rare condition where endometrial tissue grows in the rectum, causing pain during bowel movements, especially during menstruation.
  • Pudendal Neuralgia: Pain in the distribution area of the pudendal nerve, which can be exacerbated by sitting or bowel movements, though this is more commonly associated with chronic pain rather than pain specifically during bowel movements.