Understanding Lower Gastrointestinal Bleeding: A Junior Doctor's Guide

Lower gastrointestinal bleeding (LGIB) is a common yet complex emergency that can present in various ways, from minor rectal bleeding to life-threatening hemorrhage. As junior doctors, mastering the approach to LGIB involves knowing the right questions to ask, the appropriate investigations to perform, and the essential steps for effective management.

Taking a Comprehensive History

• Onset and Duration:

• When did the bleeding start? Establishing the onset helps differentiate between acute and chronic sources.

• Is the bleeding continuous or intermittent? This may indicate different pathologies, such as diverticular disease versus malignancy.

• Characteristics of the Blood:

• Is the blood bright red or dark? Bright red blood often suggests bleeding from the lower rectum or colon, while dark or tarry stool (melena) can indicate bleeding from higher up in the gastrointestinal tract.

• Is there a presence of clots or mucus? This can provide clues about the location and severity of the bleeding.

• Associated Symptoms:

• Are you experiencing abdominal pain? Pain with bleeding might suggest conditions like diverticulitis or inflammatory bowel disease (IBD).

• Any recent changes in bowel habits? Diarrhea or constipation can point towards specific diagnoses like infectious colitis or colorectal cancer.

• Past Medical History:

• Do you have a history of gastrointestinal disorders? Conditions like Crohn's disease, ulcerative colitis, or a history of colorectal cancer are important to note.

• Have you had any recent surgeries or procedures? Recent interventions can sometimes lead to bleeding complications.

• Medications and Allergies:

• Are you currently taking any anticoagulants or antiplatelet agents? Medications such as warfarin or aspirin can increase bleeding risk.

• Do you have any allergies to medications? This information is crucial for safe prescribing.

• Social History:

• Do you consume alcohol? Excessive alcohol use can contribute to gastrointestinal bleeding.

• Do you use any recreational drugs? Certain drugs can also affect gastrointestinal bleeding risk.

Investigations to Perform

• Initial Assessment:

• Vital Signs: Check for signs of hemodynamic instability such as tachycardia, hypotension, or signs of shock.

• Hemoglobin and Hematocrit: These can help assess the extent of blood loss and guide treatment decisions.

Laboratory Tests:

• Complete Blood Count (CBC): To evaluate anemia and leukocyte count, which can help in distinguishing infectious causes.

• Electrolytes and Renal Function Tests: To assess the impact of bleeding on renal function and electrolyte balance.

• Imaging Studies:

• Abdominal Ultrasound: Useful for assessing free fluid in the abdomen, which may suggest significant bleeding.

• CT Abdomen and Pelvis: A contrast-enhanced CT scan can help identify the source of bleeding, such as diverticulitis or malignancy.

• Endoscopic Evaluation:

• Colonoscopy: Often used if the bleeding source is suspected to be in the colon or rectum. It allows direct visualization and potential therapeutic interventions.

• Flexible Sigmoidoscopy: Can be used if the bleeding is more localized to the rectum or sigmoid colon.

• Stool Studies:

• Stool Occult Blood Test: Useful for detecting hidden blood in the stool, which can be indicative of gastrointestinal bleeding.

Management Plan

• Resuscitation:

• Fluid Replacement: Administer intravenous fluids to maintain blood pressure and hydration. Consider blood transfusions if there is significant blood loss or if the patient is symptomatic.

• Monitoring: Continuous monitoring of vital signs and urine output is crucial to assess the response to treatment.

• Address the Source:

• Medications: Review and potentially reverse any anticoagulant therapy if appropriate. Use proton pump inhibitors if there’s a suspicion of upper GI bleeding contributing to the presentation.

• Surgical Intervention: Consult surgical teams if there is evidence of a need for surgical intervention based on imaging and endoscopic findings.

• Specialist Referral:

• Gastroenterology: For further evaluation and management of chronic conditions or if endoscopic intervention is required.

• Hematology: If there are underlying coagulopathies or issues related to blood disorders.

• Follow-Up:

• Patient Education: Ensure the patient understands the signs of rebleeding and the importance of follow-up appointments.

• Long-Term Management: Coordinate with primary care or gastroenterology for long-term management of chronic conditions or surveillance for potential malignancies.