Differential Diagnosis:                   Ref:  Physician Online Clinical Outlines 2001

1. Hemorrhoid, anal fissures or fistulas, proctitis, or rectal trauma

2. Diverticulosis or diverticulitis; Meckel's diverticulum of the distal ileum;

3. Arterio-Venous Malformation (AVM) or Angiodysplasia (upper or lower)

4. Neoplastic Tumor - Colon Carcinoma or Benign Colon Polyps

5. Infection - Infective colitis

6. Mesenteric Ischemia, Infarction, Ischemic colis in elderly

7. Ulcerative Colitis or Regional Enteritis

8. Pneumatosis cystoides intestinales

9. Intussusception

Dx. tests:
Stools for Guiac tests, anal & rectal examinatin, anoscope, sigmoidoscopy, colonoscopy, angiography, radiolabeled erythrocyte scanning, exploratory laparostomy; stools for bacterial & parasite study.

Urgent Colonoscopy for the Diagnosis and Treatment of Severe Diverticular Hemorrhage
NEJM Jan 13, 2000 - 342:2 Dennis M. Jensen (UCLA)

Conclusions. Among patients with severe hematochezia and diverticulosis, at least one fifth have definite diverticular hemorrhage. Colonoscopic treatment of such patients with epinephrine injections, bipolar coagulation, or both may prevent recurrent bleeding and decrease the need for surgery. (N Engl J Med 2000;342:78-82.)

The Role of Endoscopy in Managing Acute Lower Gastrointestinal Bleeding (Editorial)
The New England Journal of Medicine -- January 13, 2000 -- Vol. 342, No. 2

In this issue of the Journal, Jensen et al. report their experience with the use of colonoscopy performed on an urgent basis for the diagnosis and treatment of acute hemorrhage from colonic diverticulosis. (1) The study has two key messages.

  1. The endoscopic findings that characterize recent hemorrhage (routinely used in the evaluation of acute upper gastrointestinal bleeding) are also useful in establishing the diagnosis in a subgroup of patients with colonic diverticular hemorrhage.
  2. That conventional endoscopic therapy  prevents recurrent bleeding (-- by means of injection, coagulation, or both -- for the control of bleeding from a visible vessel associated with a colonic diverticulum ).

The findings of Jensen et al. suggest that colonoscopy has an important role in the diagnosis and treatment of acute lower gastrointestinal bleeding. However, the timing of colonoscopy and the best type of endoscopic therapy remain uncertain. It is also uncertain whether the results of treating acutely bleeding colonic diverticula can be extrapolated to other types of bleeding colonic lesions such as those due to angiectasis, polypectomy sites, and protruding visible vessels without associated mucosal lesions, known as Dieulafoy lesions. (5)

These encouraging results notwithstanding, it should be noted that Jensen et al. studied a small subgroup of all patients with acute gastrointestinal bleeding. Lower gastrointestinal bleeding accounts for only 20 percent of all episodes of acute gastrointestinal bleeding, and the reported incidence of lesions that can be treated endoscopically is low. (6,7,8,9) Nearly half of patients who are hospitalized with acute lower gastrointestinal hemorrhage have bleeding due to diverticulosis; in approximately 20 percent of cases, no explanation is found for the bleeding, despite the use of endoscopy. (7,8,9) The outcome of patients with diverticular hemorrhage is good, with low rates of recurrent bleeding and no significant risk of death due to bleeding over years of follow-up, despite the fact that such patients are typically 65 years of age or older. (6,10) At most, 20 percent of patients with diverticular hemorrhage may have bleeding from a diverticulum that can be identified and treated during endoscopy. (1)

Jensen et al. studied "urgent" colonoscopy, which they defined as that performed within 6 to 12 hours after hospitalization or the diagnosis of hematochezia, and not "emergency" colonoscopy. Scheduling the examination within a reasonable period, whether 6 hours or 24 hours after arrival at the hospital, is useful for three reasons.  

  1. there is time for the bowel to be cleansed.
  2. this is the period within which recurrent bleeding most often occurs, so endoscopy at this time increases the opportunity for diagnosis and effective treatment.
  3. avoiding longer delays may contribute to efficient management -- for example, if a bleeding cancer is identified.

Although successful performance of colonoscopy without bowel cleansing has been reported, this practice is questionable. Jensen et al. used high-volume polyethylene glycol bowel lavage. Cleansing lavage may be best at removing large amounts of debris and diluting any blood that accumulates from recurrent bleeding during the procedure. Stimulant cathartic preparations, in contrast, may not adequately remove blood and clots and at the same time may subject the patient to undesirable fluctuations in electrolyte and fluid levels. No data are available about the safety and efficacy of urgent bowel preparation in patients with acute bleeding. In the study by Jensen et al., all patients underwent lavage until the effluent was clear.

Patients with severe lower gastrointestinal hemorrhage, especially those taking nonsteroidal antiinflammatory medications, should first be examined with emergency upper endoscopy to exclude the possibility of a bleeding duodenal ulcer.  Some of the patients in the study by Jensen et al. underwent push enteroscopy to rule out lesions in the proximal small intestine. Enteroscopy is not commonly used to evaluate an initial episode of acute lower gastrointestinal bleeding. Push enteroscopy does have a role, however, in the assessment of patients who have unexplained recurrent bleeding but in whom colonoscopy after careful cleansing of the colon and after upper endoscopy is not diagnostic.

There are a variety of options for endoscopic therapy in patients with acute lower gastrointestinal bleeding. No one method or combination of methods is superior.

Endoscopic therapy is indicated only when a discrete source of bleeding is identified on the basis of stigmata of recent hemorrhage, whether bleeding is active or inactive. Only about 20 percent of patients with lower gastrointestinal bleeding may have a lesion that can be treated through the endoscope.

In conclusion, despite the small number of patients treated endoscopically in their study, Jensen et al. have provided compelling data. Their findings suggest that colonoscopy should be considered early in the evaluation of patients with acute lower gastrointestinal bleeding and should follow closely after bowel preparation by lavage. A finding of active bleeding or nonbleeding stigmata of recent hemorrhage from a discrete lesion, such as a diverticulum, suggests that the patient is at high risk for recurrent bleeding, and the role of directed endoscopic therapy in such patients should be evaluated in prospective and multicenter studies.

Christopher J. Gostout, M.D. ,   Mayo Clinic, Rochester, MN 55905