Results
Cause of your symptoms
Your abdominal pain and constipation are probably due to functional bowel problems if they settle quickly and the rectal bleeding is probably from piles.
Advice
Try the treatments outlined below for two weeks but if your abdominal pain prevents any of your activities including working or sleeping see your GP.
Treatments
Take laxatives for your constipation and if necessary antispasmodic tablets for your abdominal pain or discomfort. Try careful cleaning around your bottom for your pile symptoms and if necessary creams and suppositories. Try to avoid straining too much when opening your bowels. 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 with 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.