From the Guidelines
A colonoscopy following a positive fecal occult blood test (FOBT) should typically be performed as an outpatient procedure, not as an inpatient procedure, as most colonoscopies for FOBT follow-up can be safely and effectively conducted in an ambulatory setting with same-day discharge 1. The procedure itself usually takes 30-60 minutes, with recovery time of 1-2 hours before the patient can return home. Outpatient colonoscopy is cost-effective, convenient for patients, and does not compromise quality of care for most individuals.
Inpatient colonoscopy should be reserved for patients with specific risk factors such as severe comorbidities (advanced heart failure, severe COPD, unstable angina), high bleeding risk, severe frailty, or those requiring intensive monitoring. The decision should be individualized based on the patient's clinical status, with most patients with only a positive FOBT not meeting criteria for inpatient admission.
- Key considerations for inpatient versus outpatient colonoscopy include:
- Patient's overall health and risk factors
- Ability to tolerate bowel preparation and sedation
- Need for intensive monitoring or emergency intervention
- Resource utilization and healthcare costs The bowel preparation, sedation protocols, and technical aspects of the procedure remain the same regardless of setting, but the resource utilization and healthcare costs differ significantly between inpatient and outpatient approaches 1.
From the Research
Colonoscopy for Positive Occult Blood Test
- The decision to perform a colonoscopy as an inpatient procedure in patients with a positive occult blood test (FOBT) depends on various factors, including the patient's overall health, the presence of symptoms, and the likelihood of finding a significant lesion 2, 3.
- A study published in 1998 found that urgent unprepped colonoscopy can be performed safely and effectively in patients with acute lower gastrointestinal bleeding, with a high rate of success in localizing and treating the cause of bleeding 4.
- However, the same study excluded patients who were only hemoccult positive or had an upper gastrointestinal source of bleeding, suggesting that the approach may differ for patients with positive FOBT results without overt bleeding.
- Guidelines for follow-up after positive FOBT results recommend colonoscopy as the definitive method of diagnosis and often treatment 2, but do not specify whether this should be done as an inpatient or outpatient procedure.
- A study published in 2022 found that patients with a positive immunochemical FOBT result after a recent colonoscopy had a low prevalence of advanced neoplasia, and that a previous colonoscopy performed within 4 years was protective against colorectal cancer 5.
- Another study published in 2010 found that total colonoscopy following a positive FOBT result detected early colorectal cancer more frequently than advanced colorectal cancer 6.
- The American College of Gastroenterology and other professional organizations recommend colonoscopy as the primary screening modality for patients with positive FOBT results, but do not provide specific guidance on the timing or setting of the procedure.
Factors Influencing the Decision
- The presence of symptoms, such as abdominal pain, bleeding, or changes in bowel habits, may influence the decision to perform a colonoscopy as an inpatient procedure 4, 3.
- The patient's overall health, including the presence of comorbidities or underlying medical conditions, may also impact the decision 4, 3.
- The likelihood of finding a significant lesion, such as colorectal cancer or advanced adenoma, may be higher in patients with positive FOBT results, particularly if they have a family history of colorectal cancer or other risk factors 2, 5, 6.