Differential Diagnosis for a 67-year-old Patient with Intermittent Rectal Bleeding

Single Most Likely Diagnosis

• Hemorrhoids: Given the patient's history of hemorrhoids and the intermittent nature of the bleeding, which has stopped for a couple of months, hemorrhoids are the most likely cause. The fact that the bleeding occurs 1-2 times and then resolves, only to return a couple of months later, aligns with the typical presentation of hemorrhoidal bleeding.

Other Likely Diagnoses

• Diverticulosis: Although the patient had a colonoscopy 10 years ago, diverticulosis could have developed since then. The intermittent nature of the bleeding could be consistent with diverticular disease, especially in the absence of other symptoms like abdominal pain.
• Anal Fissure: This could cause intermittent bleeding, especially if the fissure is not constantly open or if it heals and then re-opens. However, anal fissures typically cause more pain than what is described here.
• Internal Rectal Prolapse: This condition can cause intermittent bleeding due to the prolapse of the rectal mucosa through the anus, which might not always be symptomatic.

Do Not Miss Diagnoses

• Colorectal Cancer: Although the patient had a colonoscopy 10 years ago, the risk of colorectal cancer increases with age, and new cancers can develop. Any rectal bleeding in a patient over 50 should prompt consideration of colorectal cancer, even if the bleeding is intermittent and has stopped.
• Angiodysplasia: These are vascular lesions in the colon that can cause bleeding. They are more common in older adults and can present with intermittent, painless bleeding.
• Inflammatory Bowel Disease (IBD): Conditions like ulcerative colitis or Crohn's disease can cause rectal bleeding, although they typically present with other symptoms like diarrhea, abdominal pain, and weight loss.

Rare Diagnoses

• Rectal Ulcer: A solitary rectal ulcer can cause intermittent bleeding, usually associated with straining during bowel movements or constipation.
• Dieulafoy's Lesion: A rare cause of gastrointestinal bleeding, characterized by a small mucosal defect with an exposed, often large-caliber, artery at its base. It can cause significant, intermittent bleeding.
• Intussusception: Although more common in children, intussusception can occur in adults and cause intermittent bleeding, abdominal pain, and a palpable mass. It is a rare cause of rectal bleeding in adults.