. 2022 Sep 23;8(5):2369–2402. doi: 10.3390/tomography8050198

Table 2.

Recommendations, advantages and limitations of the use of the various endoscopic and imaging techniques.

	Recommendations	Advantages	Disadvantages
Endoscopy	Initial procedure for the diagnosis and treatment of UGIB and LIGB in haemodynamically stable patients.	Locates the source of bleeding and allows for haemostatic treatment in most patients. Tissue samples can be taken in the event of suspected malignancy.	It may not be universally available. Limitations in terms of the visualisation of the whole small intestine. Diagnostic exploration limited by the presence of abundant active bleeding, food residues and faeces.
Enteroscopy and Videocapsule Endoscopy (VDE)	Possible diagnostic use in the detection of focal SBB/MGIB and LGIB bleeds in haemodynamically stable patients. Endoscopic procedures, such as single or double balloon enteroscopy or retrograde ileoscopy may be indicated to define the diagnosis and treatment if the source of bleeding was found with the VDC.	Visualises the small intestine mucosa directly with the ability to identify a potential source of active bleeding.	Enteroscopy: an invasive procedure that requires sedation. Risk of perforation. Need for specialised staff and level II centres. It is not used in UGIB. VDC: long duration of examination and analysis time of acquired images (>8 h); furthermore, it does not allow for therapeutic haemostasis. Need for specialised staff and level II centres. It is not used in UGIB.
Scintigraphy	Possible diagnostic use in the search for focal SBB/MGIB and LGIB in haemodynamically stable patients.	It can detect low rates of arterial or venous bleeding, including intermittent. Non-invasive. No bowel preparation required.	Often, it does not allow for the exact identification of the bleeding site. High radiation dose applied. It requires time and specialised staff that are not available in urgent contexts. It is not used in UGIB.
Angiography	Possible diagnostic use in the screening for focal SBB/MGIB and LGIB in haemodynamically stable patients. Recurrent/continuous bleeding after colonoscopic treatment for LGIB. For UGIB, patients with acute bleeding with negative endoscopy or in whom endoscopy could not find the source (especially haemodynamically unstable patients). Possible therapeutic use for focal UGIB, MGIB and LGIB that cannot be treated endoscopically.	It can identify and treat gastrointestinal bleeding, if detected, also allowing for the selective exclusion of small vessels. High spatial resolution.	It requires a high bleeding rate for detection of the bleeding source. Invasive and time-consuming procedure for diagnostic purposes. High radiation dose applied. Requires the use of contrast media. Risk of bowel wall ischaemia [6,7,8]. Need for specialised staff and level II centres [9,10,11].
Magnetic Resonance Imaging (MRI)	Possible use for diagnosis and follow-up of IBD. Not indicated for the detection of active GI bleeding. Non-routine use in occult bleeding and obscure SBB/MGIB in haemodynamically stable patients.	High contrast and spatial resolution. Possibility of using ultra-fast sequences to examine intestinal motility (cine-MRI). No ionising radiation.	Not widely available. Long procedure. Need for proper preparation. Use of contrast media. Not therapeutic. It is not used in UGIB.
CT	The technique of choice for all SBB/MGIB and LGIB with active bleeding in hemodynamically stable (or stabilised) patients; UGIB with negative endoscopy, or endoscopy unable to identify the source (comparable to angiography).	Widely available. Quick identification of the bleeding source with precise anatomical localisation. Containment of the radiation dose with advanced technology (dual energy).	It may be less sensitive than radionuclide imaging. It can underestimate intermittent bleeding. Not therapeutic. Radiation dose. Requires the use of contrast medium.