Over half of your blood contains plasma, which is made of water, salts, and protein, in addition to red blood cells, white blood cells, and platelets. Red blood cells (RBC) deliver oxygen from your lungs to your tissues and organs, including your gastrointestinal system.
Gastrointestinal bleeding (GI bleed) or gastrointestinal haemorrhage (GIB); means any form of bleeding in the gastrointestinal tract that locationally can be from the mouth to the rectum.
There are two main types of gastrointestinal bleeding: upper gastrointestinal bleeding and lower gastrointestinal bleeding. The diagnosis can begin with small amounts of bleeding detected in the faecal occult blood test, followed up with physical examinations, medical history and further medical investigations to locate the area of bleeding, endoscopy or medical imaging tools.
Small amounts of bleeding over a long period of time may cause iron-deficiency anaemia resulting in general fatigue or mild chest pain. Other symptoms may include abdominal pain, shortness of breath, pale skin, dizziness, or fainting. In some cases, there are no symptoms and persistent small bleeds go undetected.
Significant gastrointestinal blood loss over a short time may include symptoms such as vomiting blood, bloody stool, or black tarry stool.
The causes of upper GI bleeds can include peptic ulcer disease, oesophageal varices related to liver cirrhosis and cancer, among other diseases. The causes of lower GI bleeds may include haemorrhoids, colon cancer, and a variety inflammatory bowel disease. Early detection can improve health conditions and my prevent serious gastrointestinal damage.
References:
1. The effectiveness of FOBT vs. FIT: A meta-analysis on colorectal cancer screening test Maryam Mousavinezhad, 1 Reza Majdzadeh,* 2 Ali Akbari Sari, 3 Alireza Delavari, 4 and Farideh Mohtasham 5 Med J Islam Repub Iran. 2016; 30: 366.
2. Effectiveness of screening for colorectal cancer with a faecal occult-blood test, in Finland J Pitkäniemi,1 2 K Seppä,1 M Hakama,1 3 O Malminiemi,4 T Palva,5 M-S Vuoristo,5 H Järvinen,6 H Paimela,7 P Pikkarainen,8 A Anttila,1 L Elovainio,1 T Hakulinen,1 S Karjalainen,9 L Pylkkänen,9 M Rautalahti,10 T Sarkeala,1 H Vertio,9 N Malila1 3 BMJ Open Gastro 2015;2:e000034. doi:10.1136/bmjgast-2015- 000034