Lower gastrointestinal bleeding
Arbitrarily defined as overt intraluminal bleeding from a point below the ligament of Treitz. May present as haematochezia or clots. Massive upper GI haemorrhage may result in passage of blood and clots per rectally.
The approach is conservative initially with resuscitation with transfusion as necessary. If bleeding fails to stop, the approach is to identify a source and treat it with radiological or surgical intervention.
- This may not identify a cause as blood may coat the bowel wall, obscuring adequate examination. Diverticular disease is easily demonstrated with colonoscopy. Even is a cause if not found, colonoscopy may identify a cut-off point, above which there is no blood. This helps target subsequent intervention, if required (e.g. segmental bowel resection instead of blind subtotal colectomy, or targetted mesenteric angiography of inferior mesenteric artery rather than superior mesenteric).
- To exclude an upper GI cause.
- Mesenteric angiography
- Performed percutaneous with intravenous contrast dye. Requires brisk bleeding of at least 1-2ml/minutes.
- CT 'angiography'
- Intravenous contrast is administered and images are capture in the arterial and delayed phase. Maybe more sensitive than standard percutaneous angiography, but not therapeutic. Pooling of the dye allows localisation of the bleeding, allowing a more selective approach with percutaneous angiography +/- embolisation. 
- Diverticular disease
- Inflammatory bowel disease
- Anorectal conditions such as haemorrhoids and anal fissure
- Ischaemic colitis
- Angiodysplasia and arterio-venous malformations
- ↑ Sabharwal R, Vladica P, Chou R, Law WP. Helical CT in the diagnosis of acute lower gastrointestinal haemorrhage. European journal of radiology. 2006 May; 58(2):273-9.(Link to article – subscription may be required.)
- ↑ Yoon W, Jeong YY, Shin SS, Lim HS, Song SG, Jang NG, Kim JK, Kang HK. Acute massive gastrointestinal bleeding: detection and localization with arterial phase multi-detector row helical CT. Radiology. 2006 Apr; 239(1):160-7.(Link to article – subscription may be required.)
- ↑ Scheffel H, Pfammatter T, Wildi S, Bauerfeind P, Marincek B, Alkadhi H. Acute gastrointestinal bleeding: detection of source and etiology with multi-detector-row CT. European radiology. 2007 Jun; 17(6):1555-65.(Link to article – subscription may be required.)
- ↑ Duchesne J, Jacome T, Serou M, Tighe D, Gonzales A, Hunt JP, Marr AB, Weintraub SL. CT-angiography for the detection of a lower gastrointestinal bleeding source. The American surgeon. 2005 May; 71(5):392-7.
- ↑ Laing CJ, Tobias T, Rosenblum DI, Banker WL, Tseng L, Tamarkin SW. Acute gastrointestinal bleeding: emerging role of multidetector CT angiography and review of current imaging techniques. Radiographics : a review publication of the Radiological Society of North America, Inc. 2007 Jul-Aug; 27(4):1055-70.(Link to article – subscription may be required.)