There is a possibility of lactose intolerance or a stomach bug or parasites.
Don't give him any milk while he is ill.
Wishing him a speedy recovery.
This could also be a symptom of a food allergy. My daughter had the same symptoms, loose stool with mucus and streaks of blood. It turned out she was allergic to milk. She is 12 now and has completely grown out of it.
I would contact your pediatrician as soon as possible to get a proper diagnosis. Best of luck. Hang in there.
Brenda
Don't delay and get your two year old seen by the doctor.
He may have some problems in the bowels, or may be suffering from constipation, or may have worms. This is very common with young children so don't worry too much about that. Either way the doctor will help by examining your son to find out what is the cause and if it is due to constipation will prescribe you a cream to apply around the rectum and a medicine to soften the stools. If it is found that he has worms or parasites, then the doctor will be able to prescribe medication to get rid of them.
Make sure that you give your son plenty of water and juice. Don't give him any chocolate (that tends to constipate) and cut down on sweets. Give him fresh washed fruit to eat and vegetables. Give him his favourite fruit and veg. For toast use wholemeal and if he likes porridge give him that.
Anything untoward with young children should always be investigated.
Best wishes.
What has he been eating? Must be binding or disrupted the intestinal cycle.
Less binding food, lots of water. Call the doctor