What is the most likely diagnosis for a patient presenting with isolated rectal bleeding, which is common and can be preventable?

Hemorrhoids (Answer: B)

The most likely diagnosis is hemorrhoids, which are the most common cause of isolated rectal bleeding and are both common and preventable through dietary and lifestyle modifications. 1

Why Hemorrhoids is the Correct Answer

The American Gastroenterological Association explicitly states that hemorrhoids are a "common affliction in the adult population" and that bleeding is the most common presenting symptom. 1 The key clinical features that point to hemorrhoids in this case include:

• Isolated bright red rectal bleeding without other symptoms is the hallmark presentation of hemorrhoids 1
• Hemorrhoids are preventable through adequate fiber and water intake, which is the cornerstone of medical therapy 1
• The provider's statement that this is "common and can be preventable" directly aligns with hemorrhoidal disease management guidelines 1

Why Other Options Are Less Likely

Anal Fissure (Option A)

• The cardinal symptom of anal fissure is postdefecatory pain, not isolated bleeding 1
• While fissures can cause minor rectal bleeding, pain is the dominant feature that would have been mentioned if present 1
• Fissures are less "common" than hemorrhoids in the general population 1

Juvenile Polyp (Option C)

• Juvenile polyps are not described as "preventable" conditions [@general medical knowledge@]
• They are less common than hemorrhoids and typically occur in children [@general medical knowledge@]
• Not the most frequent cause of rectal bleeding in the general population

Intussusception (Option D)

• Intussusception presents as a surgical emergency with severe abdominal pain, not isolated rectal bleeding [@general medical knowledge@]
• The provider would not describe this as "common and preventable" [@general medical knowledge@]
• This is primarily a pediatric emergency, not a routine outpatient diagnosis

Critical Clinical Caveat

Even when hemorrhoids are identified, proper evaluation is mandatory. The American Gastroenterological Association emphasizes that "when hemorrhoids are simply assumed to be the cause, other pathology is too often overlooked." 1 All patients with rectal bleeding should undergo:

• Minimum of anoscopy and flexible sigmoidoscopy for bright-red rectal bleeding 1
• Complete colonoscopy if the patient has risk factors for colorectal cancer (age, family history), atypical bleeding patterns, or no source evident on anorectal examination 1
• The estimated risk of colorectal cancer in patients with rectal bleeding ranges from 2.4-11% 1

Prevention Strategy for Hemorrhoids

The preventable nature mentioned by the provider refers to:

• Adequate fiber intake (cornerstone of medical therapy) 1
• Adequate water intake 1
• Avoiding prolonged straining and constipation 2
• These measures prevent hemorrhoid formation and progression 1