What is the likely diagnosis for a patient experiencing hematochezia with a positive fecal occult blood test?

The likely diagnosis for a patient experiencing hematochezia, or the passage of fresh blood through the anus, combined with a positive fecal occult blood test, is internal hemorrhoids. Internal hemorrhoids are located above the dentate line of the anal canal and are covered by rectal mucosa, which is sensitive to bleeding. They are often the cause of bright red blood on the toilet paper or in the stool when they bleed, making them a plausible source of the observed symptoms.

A positive fecal occult blood test indicates the presence of blood that may not be visible to the naked eye, suggesting a bleeding source within the gastrointestinal tract. Internal hemorrhoids are particularly known for causing such bleeding, especially during bowel movements when straining can exacerbate the condition.

In contrast, external hemorrhoids are typically associated with pain and swelling, but they are less likely to cause significant hematochezia that would result in a positive fecal occult blood test. Conditions like bleeding peptic ulcers generally present with different patterns of blood loss, often leading to darker stools (melena) due to upper gastrointestinal bleeding. Rectal fissures can cause pain and bleeding but are less common as a source of positive fecal occult blood without the presence of significant other symptoms.