Lower Gastrointestinal Bleeding - A Frequent Cause of Hospitalization

Introduction

Gastrointestinal bleeding is the bleeding that occurs in the gastrointestinal tract from mouth to anus. It is divided into two parts that are upper gastrointestinal bleeding and lower gastrointestinal bleeding. In this article, we will talk about lower gastrointestinal bleeding. Lower gastrointestinal bleeding is the bleeding that occurs distal to the ligament of Treitz. The ligament of Treitz is the suspensory muscle of the duodenum (part of the large intestine) that connects the end of the duodenum and the beginning of the jejunum (part of the small intestine). This ligament is the point of differentiation between upper and lower gastrointestinal bleeding. The severity of lower gastrointestinal bleeding can vary from mild to severe, and it can be life-threatening.

What Are the Types of Lower Gastrointestinal Bleeding?

There are three types of lower gastrointestinal bleeding:

1. Massive - This type is usually seen in patients of age above 65 years who present with comorbidities. The patients with this type are hemodynamically unstable with a heart rate less than or equal to 100 per minute, systolic blood pressure less than or equal to 90 mmHg, and less urine output. Blood tests reveal hemoglobin levels less than or equal to 6 g/dl. Patients with this type show hematochezia, which is bright red blood passing through the rectum. The causes of this type are mostly angiodysplasias and diverticulosis. It has a high mortality rate of 21 percent.

2. Moderate - This type of lower gastrointestinal bleeding can be seen in patients of any age. The patients are hemodynamically stable. The patients show hematochezia or melena. The cause of this type can be neoplastic, inflammatory, benign anorectal, infectious or congenital disease.

3. Occult - This type also occurs in patients of any age. Patients are hemodynamically stable. Patients suffer from microcytic hypochromic anemia due to chronic blood loss. The possible causes of this type are neoplastic, inflammatory, and congenital diseases.

What Are the Signs and Symptoms of Lower Gastrointestinal Bleeding?

Lower gastrointestinal bleeding exhibits apparent blood (overt) or, at times, hidden or invisible blood (occult). Apparent bleeding presents bright red blood passing through the anus along with stools, maroon blood or blood clots, and sometimes a black tarry stool. Invisible or hidden blood presents in the form of anemia, which is a low red blood cell count. Other symptoms are:

• Feeling tired.

• Faintness or dizziness when bleeding is heavy.

• Pain in the abdomen.

• Breathing difficulties.

• Chest pain.

• Lightheadedness.

• Patients can go into shock when there is heavy abrupt bleeding. The symptoms of shock are rapid pulse, decreased blood pressure, low urine output, and unconsciousness.

What Are the Causes of Lower Gastrointestinal Bleeding?

The possible causes that lead to lower gastrointestinal bleeding are:

1. Diverticular Disease - It involves the development of small pouches in the large intestine. If these pouches get infected or inflamed, it is known as diverticulitis. Diverticular disease is one of the most common causes of lower gastrointestinal bleeding.

2. Angiodysplasias -It is the second most common cause of lower gastrointestinal bleeding. Angiodysplasias are abnormal blood vessels that are responsible for bleeding from the large intestine.

3. Tumors - Benign or malignant tumors on the gastrointestinal tract can weaken the lining of the tract and hence lead to bleeding.

4. Colon Polyps - Small mushroom-like cell growths on the lining of the large intestine that can be benign, precancerous, or cancerous can cause bleeding.

5. Hemorrhoids - Hard stools or sitting or straining for a long time in the toilet bowl can cause swollen veins in the anus or lower rectum, leading to bleeding. Hemorrhoids are similar to varicose veins.

6. Anal Fissures - Hard stools can cause tiny tears in the anus. This may lead to the painful passage of bowel movements and bleeding along with stools.

7. Inflammatory Bowel Disease (IBD) - This includes two conditions, Crohn's disease (inflammation of the small and large intestine), and ulcerative colitis (inflammation and sores in the large intestine and rectum).

8. Proctitis - Rectal bleeding caused due to the inflammation of the lining of the rectum.

What Are the Complications of Lower Gastrointestinal Bleeding?

• Anemia - It is the condition in which the blood does not have enough healthy red blood cells to carry oxygen to the body’s organs.

• Shock - Due to heavy bleeding, the patient can go into shock with symptoms like unconsciousness, decreased blood pressure, rapid pulse, and low urine output.

• Death - Lower gastrointestinal bleeding is noted to have caused mortality of 24.3 percent in shock and 2.67 percent without shock.

What Are the Risk Factors for Developing Lower Gastrointestinal Bleeding?

• Medicines such as nonsteroidal anti-inflammatory drugs (NSAIDs).

• Excessive use of alcohol and smoking.

• Delayed screening of colon polyps and cancer.

• Conditions that may lead to angioectasias (vascular malformations throughout the gastrointestinal tract), such as old age, aortic stenosis, and blood thinner medications.

How to Diagnose Lower Gastrointestinal Bleeding?

1. Blood Tests: This includes CBC (complete blood count), liver function tests, lactate levels, electrolyte levels, and coagulation studies. The BLEED criteria can be applied to any patient with lower gastrointestinal bleeding. It includes:

• Ongoing Bleeding - Red or maroon blood passing through the anus or red blood emesis (vomiting).

• Low Systolic Blood Pressure - Less than 100 mmHg

• Elevated Prothrombin Time - More than 1.2 times the normal value.

• Erratic Mental Status - Altered level of consciousness due to any reason.

• Unstable Comorbid Disease - Any other disease that can lead to ICU (intensive care unit) admission without the presence of gastrointestinal bleeding.

2. Stool Test: It is done to detect the presence of blood in the stool that can be hidden or invisible.

3. Imaging Tests: Using an intravenous chemical, a bleeding scan is conducted to detect bleeding in the intestine. A CT (computed tomography) scan can also help diagnose bleeding in the large intestine.

4. Colonoscopy: Using a colonoscopy, a thin tube with an attached camera, a thorough evaluation of the large intestine is done for any lesions that can cause bleeding.

5. Capsule Endoscopy: This test involves ingesting a capsule with light and a camera that transmits images to a recorder worn by the patient on the belt. After the test is done, the capsule passes out along with the stools.

What Are the Treatment Options for Lower Gastrointestinal Bleeding?

The initial management of lower gastrointestinal bleeding includes assessment of the blood loss by the doctor and giving intravenous fluids and oxygen through a mask.

Non-surgical Therapeutic Options -

Once the site of bleeding is localized, the following options are considered depending on the cause:

• In cases where the cause of bleeding is diverticular diseases, colonoscopy with bipolar coagulation is preferred, along with adrenaline injections or metallic clips.

• Resection of the bowel segment is done in case of recurrent bleeding.

• Thermal therapy, such as electrocoagulation and argon plasma coagulation, is preferred when the cause is angiodysplasias.

• In patients with ischemic colitis, conservative management, such as nothing by mouth (NPO) and intravenous hydration, is done.

• Vasoconstrictive agents such as vasopressin are recommended in cases where the site of bleeding cannot be determined. Superselective embolization is useful when vasopressin is unsuccessful.

Surgery -

Surgery involves removing the infected part of the intestine. Surgery is indicated in the following cases:

• Persistent and recurrent bleeding.

• Active, persistent bleeding with unstable hemodynamic parameters that is refractory to aggressive resuscitation.

• When more than four units of packed red blood cells are transfused in a 24 hours period with active or recurrent bleeding.

Conclusion

Lower gastrointestinal bleeding accounts for about 20 to 33 percent of all episodes of gastrointestinal bleeding. It can be painless or painful, can be mild or severe, and can also be life-threatening. Some precautions recommended by doctors include limited use of alcohol and smoke and medications like NSAIDs. It is a treatable condition that includes treatment through colonoscopy, embolization, angiography, and surgery.