GastroBlog

Is there a role for fecal occult blood testing in the age of endoscopy?

In spite of widespread use of endoscopy in the diagnosis and management of digestive disorders, fecal occult testing still plays an important role in medical practice.   The conventional quaiac based stool testing has been present for over three decades.  However these traditional “hemoccult” tests have low sensitivity and poor specificity in detecting colorectal neoplasms or actual human blood in the stool.  Recently, several commercial laboratories have introduced immunochemical fecal occult blood (iFOB) tests.  These newer generations of tests use anti-hemoglobin antibodies (immmunochemical tests) to detect minute amounts of human hemoglobulin in the stool.  By detecting blood proteins, these assays are both more sensitive and specific, especially for colonic GI blood loss.  Brand names include Hemosure, Quickvue Quidel, Hema-screen.  

Settings where fecal occult blood can be useful:

1)     Evaluation of patients with abdominal pain.  Digital rectal exam should be a routine part of a physical exam in patients who present with acute abdominal pain; especially those with altered BMs.  Guaiac based tests are routinely used to detect blood in the GI tract which may be due to peptic ulcer disease, gastritis, gastrointestinal (GI) neoplasm, and intestinal lesions including regional enteritis, colitis or NSAID induced mucosal disease.  A positive iFOB is useful in further localizing bleeding originating from the colon such as Inflammatory Bowel disease (IBD), infectious colitis and ischemic colitis.

2)     Patients with diarrhea also benefit with fecal occult blood testing.  Positive test results may suggest more serious pathology beyond simple viral intestinal infections.  Further endoscopic work-up is typically undertaken in these circumstances to evaluate patients for IBD, neoplasia, mucosal GI disease and invasive pathogens.

3)     Work-up of anemia and suspected occult GI blood loss.  Positive iFOB is beneficial in the work-up of patients with anemia as it tends to localize the source of GI blood loss to the colon.   Guaiac based tests are less specific with higher false positive results.  Nonetheless repeated negative iFOB and hemoccult test results (in the presence of negative panendoscopy) tent to be reassuring and may sway the physician to pursue alternative work-up of anemia beyond GI sources

4)     Colorectal screening. Colonoscopy has become the standard of care in screening for colorectal cancer in the community.  Patients without colon polyps are advised to return in 10 years for repeat examination.   However this long time interval has not been documented to be the optimal screening period.  Therefore some physicians use in-home iFOB testing, starting 5 years after the last colonoscopy, to evaluate for microscopic blood loss from colonic neoplasia.  This may turn out to be an inexpensive option for screening asymptomatic patients in-between routine colon examinations.

Effective Treatment of Hemorrhoids in GI Practice

Internal hemorrhoids are one of the most common causes of rectal complaints and bleeding in medical practice. In spite of conservative management and topical creams, often patients tend to have recurrent symptoms.  Although many patients are referred to surgeons, 98% of internal hemorrhoids can be readily treated in the office setting and do not need excisional surgery.   Internal hemorrhoids are classified as follows:

Grade 1      Small internal hemorrhoid which do not prolapse below the dentate line

Treated with topical medication, Infrared coagulation (IRC), electrocautery

Grade 2     Hemorrhoids which prolapse with defecation, but spontaneously reduce

Treated with IRC, Electrocautery, Rubber band ligation (RBL)

Grade 3    Spontaneously prolapsing hemorrhoids which require manual reduction

Treated with RBL, or occasionally with surgery

Grade 4    Prolapsed internal hemorrhoids that are not reducible

Treated with excisional surgery

Infrared coagulation (IRC)

IRC is an office based procedure that uses a probe to deliver several two-second pulses of light energy to the base of a hemorrhoid.  This energy coagulates vessels and tethers the mucosa to the submucosal tissue resulting in superficial sclerosis and interruption of the blood supply to the hemorrhoid, causing it to shrink and recede.  The procedure is very quick and essentially painless.  It is considered one of the safest treatment modalities for treatment of internal hemorrhoids.  The IRC is ideal for Grade 1 and 2 internal hemorrhoids.

Rubber Band Ligation (RBL)

I’ve been using the O’Regan Disposable Hemorrhoid Banding System for ligation of internal hemorrhoids since January 2009. This highly effective (99%), minimally invasive procedure is performed in our offices in less than a minute, and most patients return to work that same day. Typically, we treat one hemorrhoid at a time in separate visits.

During the brief procedure, the tissue just above the internal hemorrhoid is suctioned into a specialized syringe-like apparatus and ligated with a small rubber band. This eventually causes mucosal ulceration with resultant interruption of blood flow and obliteration of the internal hemorrhoid.

Within the first 24 hours after the procedure, some patients may experience a feeling of fullness or a dull ache in the rectum. This can typically be relieved with an over-the-counter pain medication. However, most patients treated with this modality do not have significant post-procedure pain or need for analgesics.  With recent design improvements, this procedure has a ten-fold reduction in complications compared to traditional banding. We are also performing elastic band ligation of internal hemorrhoids atthe time of lower GI endoscopy.  This facilitates treatment of symptomatic hemorrhoids at the time of diagnostic colonoscopy or sigmoidoscopy.  The rubber band ligation therapy is optimal for Grade 2 and 3 internal hemorrhoids.

Rubber band Ligation

Rubber band ligation of internal hemorrhoids remains one of the most effective modes of treating internal hemorrhoids in the ambulatory care setting.  Unfortunately most primary care physicians and gastroenterologists have not been trained in this modality.  A referral to a surgeon often creates anxiety in patients about the potential for surgical intervention.  Furthermore 98% with symptomatic internal hemorrhoids could be readily treated by physicians in the medical clinic and do not require surgery.

 
Internal hemorrhoids can be readily diagnosed and graded in the office setting with the use of simple anascope or proctoscope.  However optimal visualization of the anorectal anatomy in the midst of hemorrhoidal therapy can be challenging as the physician’s field of vision is often limited as he tries to look through the pinhole of an anascope.   As such I’ve found the endoscopic approach to endoscopic band ligation provides multiple benefits.

1) Endoscopic evaluation of the lower GI tract (flexible sigmoidoscopy or colonoscopy),  in conjunction with band ligation, provides  additional diagnostic benefit to the patient and can readily exclude colitis, neoplasm, rectal ulceration, fistula and other mucosal diseases that may mimic hemorroidal bleeding.

2) Endoscopy provides great visual field of the anal canal and rectal anatomy compared to anascopy.  The images from the videoendoscope can be readily projected to a large screen monitor for real-time examination and photodocumentation.  In the retroflexed view of endoscopy, the layout of the hemorrhoidal complex and the dentate line is visualized in great detail.  Furthermore the endoscope provides more precise delivery of the rubber band at the time of ligation.

3) In the setting the of colonoscopy, the patient is prepped, sedated and comfortable throughout the procedure and typically has no recollection of the rubber band ligation.

4) Endoscopic band ligators provide for multiple hemorrhoidal banding capability.   This is in contrast to office based rubber band ligation, which is typically  performed on one hemorrhoid per session.   Hence patients typically need 1-2 sessions of endoscopic band ligation as opposed to 3-4 sessions of traditional rubber band ligation.

5) Hemorroidectomy (via endoscopic band ligation) during colonscopy is actually less expensive compared to office based rubber band ligation, due to the fact that the banding procedure is discounted by the insurance company in the setting of colonoscopy.

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Radiological imaging of the colon has undergone significant transformation in the past 50 years.  Barium enema (BE) has been in use since the early part of the 20th century for detection of intraluminal colon pathology.   The introduction of CT technology in the 1970’s provided opportunity for clinicians to be able to visuaizel 2-D images of the large intestine and be able to diagnose additional extraluminal pathology.   In the 1980’s use of BE started to deminish significantly as colonoscopy, with direct visualization of the colon, became the study of choice for evaluation of the large bowel.  As therapeutic colonoscopy and colorectal screening became more prevalent in the 1990’s and beyond, BE became essentially obsolete except in very special circumstance.  Nonetheless the American Cancer Society guidelines for  colorectal screening continued to include BE as an diagnostic option for evaluation of asymptomatic patients.  In the past decade the  CT colonography (CTC) has become the preminent tool in imaging of the large intestine.  Several studies have shown this modaility to be superior to B.E. and comparable to colonoscopy in the detection of large colon polyps and other gross pathology.   However the use of CT colonography beyond a few institutions in the country is non existent.  Due to lack of insurance reimbursement (except for very limited indications) most communities lack the software or the expertise to carry out these studies.

Further comments to follow……..

Aside from colorectal cancer (CRC) screening, rectal bleeding is one of the most common indications for referral of patients for colonoscopy.  In the vast majority of these cases the source of bleeding is typically internal hemorrhoids.  However once a diagnosis is rendered by the gastroenterologist, the management of internal hemorrhoids with topical creams is typically of limited benefit.   The most beneficial, simple and widely implemented in-office treatment of internal hemorrhoids is rubber band ligation (RBL).  In the office setting this has typically required multiple visits for ligation of each of the three major columns of internal hemorrhoids.  With the advent of endoscopic band ligation it is possible to consolidate this treatment to a single procedure.

Since most of the diagnostic colonoscopies are performed to evaluate rectal bleeding, and internal hemorrhoids are the most common cause of such bleeding (especially in younger patients), it makes sense to treat the source of the bleeding at the time of the colonoscopy.  As the patient is already prepped, sedated and monitored during the colonoscopy, ligation of internal hemorrhoids only adds another 5-10 minutes to the endoscopic procedure.  Hence this combined one-step procedure provides both diagnostic and therapeutic benefit to the patient with hemorrhoidal disease.

There are multiple medical devices available for hemorrhoidal banding in the setting of colonoscopy.  I’ve found that the Boston Scientific Speedband Superview Super7 Multiple Band Ligator to be the most efficient.  It is a small, clear view ligating unit which is attached to the tip of the endoscope.  The device can deliver up to 7 rubber bands using a single string deployment apparatus.  During the endoscopic procedure, the base of the hemorrhoid is suctioned into the clear cup and the rubber band is deployed by turning the dial at the endoscope biopsy channel.  The apparatus is virtually identical to the multiple rubber band ligator used for treatment of esophageal variceas. 

A recent article using an alternative ligator, showed that combined colonoscopy and 3-guadrant hemorrhoidal ligation in 500 patients was 93% effective in the resolution of symptoms attributed to internal hemorrhoids over a three year period.  Additional 6.6% of these patients had repeat RBL treatment with benefit and only 2.2% required hemorrhoidectomy.  None of these patients experienced post-ligation hemorrhage and only a small minority had significant pain.  (Davis, KG et. al.  Dis Colon Rectum 2007; 50: 1445-1449).

Combined colonoscopy with multiple rubber band ligation provides an effective treatment option for patients with symptomatic internal hemorrhoids.  The procedure is safe, convenient and cost effective for both the patient and the physician.  This combined modality could be readily offered to patients who present with painless rectal bleeding or chronic symptomatic hemorrhoidal disease.

Hepatitis B virus (HBV) disease – Although the incidence of acute hepatitis B is diminishing (primarily as a result of vaccination) the prevalence of chronic HBV disease seems to be on the rise due to the influx of new immigrants from endemic areas (Asia and Africa).  In addition to interferon, we now have a total of 5 well-tolerated, oral antiviral agents for treatment of this disease.  These monotherapy drugs are potent inhibitors of viral replication and are often administered long term to maximize viral, biochemical and histological remission.  Currently entecavir and tenofovir are least likely to induce resistant mutations of the virus and are typically selected as first line therapies.  Since cure rates are low for HBV, patients with chronic infection need long term surveillance for hepatocellular carcinoma with ultrasound of liver and AFP levels every 6-months.

Hepatitis C virus (HCV) disease remains the most common chronic hepatitis infection in the U.S.  Genotype 1 has the highest prevalence in the population and is the most difficult to eradicate.  One year treatment with combination of injectable interferon and ribovarin has been the mainstay of therapy for nearly a decade (with high incidents of side effects).  The addition of a new oral protease inhibitor, Telaprevir, to the current antiviral regimen has recently been shown to increase cure rates from 41% to 67%.  The medication is expected to be approved by the FDA in 2011.

Many hepatologist have recommended that chemistry laboratories adjust their ALT values with “normal” being less than 30 for men and 19 for women..  Based on these criteria, any patient that is deemed to have elevated LFTs should be screened by serological studies.  Also, any person of Asian descent, offspring or spouse of patients with chronic viral hepatitis, and individuals with high risk lifestyles need serological screening.

I am in the camp that recommends that everyone from newborn to middle age (?50) should be universaly vaccinated against the Hepatitis B virus (or preferably Hepatitis A/B vaccine —- Twinrix)