Results
Cause of your symptoms
Your abdominal pain and constipation are likely to be due to functional bowel problems if they settle quickly and the rectal bleeding is probably from veins just inside your back passage.
Advice
Try the treatments outlined below for two weeks but if your abdominal pain continues to prevent any of your activities including working or sleeping see your GP.
Treatments
Take laxatives for your constipation and if necessary take antispasmodic tablets for your abdominal pain or discomfort. Try to avoid straining too much when you have your bowels open. A pharmacist can advise on which treatments you should try.
What now?
If you get completely better nothing further needs to be done. However, if your abdominal symptoms persist for two more weeks or recur after stopping treatment see your GP.
Summary of your symptoms
You are under 50 yrs old and have abdominal pain associated with significant weight loss and or a reduction in appetite, rectal bleeding without pile symptoms and constipation.
Additional information if you see your GP
People who persistently eat less to avoid their abdominal pain and or lose a significant amount of weight may have a partial bowel blockage which requires prompt investigation in hospital.