Hi.. Thanks for contacting HCM for health query. You are a young individual with 3 weeks of diarrhoea which is annoying you. Do not worry.If there is any red signal the doctor you have should have warned you It is turning up little chronic now and may be you need to be investigated. On the advice of an in person doctor take up investigation like motion complete,ultrasound abdomen,thyroid profile,haemogram etc..and this should throw light on the issue. Till then include lot of probiotics like yogurt in your diet and replenish your self with plenty of fluids like rice gruel,fresh fruit juices with no added sugar and tender coconut water Take care.