Looking for a bit of advice. My b12 level was 58 so my doctor is starting me on the injections, 5 over a two week period. He also said they did a test which came back saying that I CAN absorb b12 but I'm just not. He's not sure what's causing it and said he hasn't come across anyone with such low b12. He's also sending me for further blood tests because my phosphate levels were low and he wants this to be rechecked. He's asked me to do a stool sample and then to see him when the results come back but he thinks I'm going to need a colonoscopy also. Is this PA? Or just a b12 deficiency, or something else? My other symptoms are; tiredness, stomach pain after eating and diarrhoea for about 5/6 months. Any advice would be appreciated!