the Causes of Rectal Bleeding: Insights from Gastroenterology

Consultation

I visited the colorectal department at the Veterans General Hospital, where I was informed that I have a mild case of hemorrhoids and some skin breakdown around the anus due to scratching.
They prescribed some topical treatment and recommended a stool test since I had experienced black stools during episodes of diarrhea, although my stools are normal otherwise.
The test revealed the presence of occult blood, which led to a recommendation for a colonoscopy.
The colonoscopy results were normal, and I wondered if the skin breakdown was related.
After the procedure, the doctor mentioned that everything looked fine and asked if I wanted to undergo an upper endoscopy.
I went to Mackay Memorial Hospital for the upper endoscopy, and the report indicated mild gastritis without ulcers.
I am concerned whether the previous hemorrhoids and the skin breakdown around the anus could be related, even though the hemorrhoids were not ruptured.
Could you please explain the possible causes of the occult blood?

mei, 30~39 year old female. Ask Date: 2004/10/11

Dr. Chen Zhiping reply Gastroenterology and Hepatology

Hello, the presence of occult blood in the stool indicates that there are blood components in the feces.
There are many reasons that can cause a positive occult blood reaction, such as consumption of red meat (beef, lamb), broccoli, or Brussels sprouts, or even eating pig or chicken blood within the last three days.
If you have not consumed these foods in the past three days, it may indicate bleeding in the gastrointestinal tract, including the rectum or anus (as little as 2 cc of blood mixed in the stool can yield a positive occult blood test).
The evaluation method is to first perform a colonoscopy to rule out any colorectal diseases.
If the cause is still not found, an upper endoscopy or even small bowel imaging may be necessary.
Since you have a slight injury in the area of your hemorrhoids, this could also potentially cause a positive occult blood reaction.
I recommend that you wait for a while until the wound heals, avoid the aforementioned foods, and then retest for occult blood in the stool.
If it remains positive, a colonoscopy should be considered, especially if there is a family history of colorectal cancer, as this would increase the risk and warrant further investigation.
Sincerely, Dr.
Chen Zhi-Ping.

Reply Date: 2004/10/11

More Info

Rectal bleeding can be a concerning symptom, and understanding its causes is crucial for appropriate management and treatment. Based on your description, it seems that you have undergone several evaluations, including a rectal examination, colonoscopy, and gastroscopy, which have provided some insights into your condition.

Firstly, it is important to note that rectal bleeding can arise from various sources within the gastrointestinal tract. Common causes include hemorrhoids (or piles), anal fissures, diverticular disease, inflammatory bowel disease (IBD), and colorectal cancer. In your case, the presence of hemorrhoids and a minor skin tear (from scratching) could indeed be contributing factors to the superficial blood observed in your stool.

Hemorrhoids are swollen veins in the lower rectum and anus that can cause bleeding, especially during bowel movements. They can be internal or external, and while they may not always cause pain, they can lead to discomfort and bleeding. If you have been experiencing constipation or straining during bowel movements, this could exacerbate hemorrhoidal symptoms.

The anal fissure, which you mentioned as a result of scratching, can also lead to bleeding. This is a small tear in the lining of the anus, often caused by passing hard stools or trauma to the area. The bleeding from fissures is typically bright red and may be accompanied by pain during bowel movements.

The black stools you reported during episodes of diarrhea could indicate upper gastrointestinal bleeding, as black, tarry stools (melena) are often a sign of blood that has been digested. However, since your colonoscopy showed no significant issues, and your gastroscopy revealed only mild gastritis, it is less likely that your black stools are related to a serious condition.

The presence of "shallow blood" in your stool, as indicated by your stool test, could be linked to the aforementioned hemorrhoids or fissures. It is essential to monitor your symptoms closely. If the bleeding persists, increases in volume, or is accompanied by other symptoms such as abdominal pain, weight loss, or changes in bowel habits, further evaluation may be warranted.

In terms of management, addressing lifestyle factors can be beneficial. Increasing dietary fiber intake, staying hydrated, and avoiding straining during bowel movements can help reduce the risk of hemorrhoids and fissures. Over-the-counter treatments, such as topical creams for hemorrhoids, may also provide relief.

Follow-up with your gastroenterologist is essential, especially if you continue to experience rectal bleeding or if new symptoms arise. They may recommend additional tests or treatments based on your ongoing symptoms and any changes in your condition.

In summary, while your current evaluations have not revealed any serious underlying conditions, the combination of hemorrhoids and a possible anal fissure could explain the superficial blood you are observing. Maintaining a healthy diet and monitoring your symptoms will be key in managing your condition effectively. If you have any concerns or if your symptoms change, do not hesitate to reach out to your healthcare provider for further guidance.

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