just get him to drink more. not just milk (which can be constipating in some children). the lack of bowel movement is not concerning as long as he is acting fine. when you are not drinking sufficient fluids the body actually pulls water from the colon to use (not the bladder). there may not be any "extra" fluid for him to urinate so this is why you need to really encourage good hydration today. signs of dehydration in children would include dry eyes (no tears) and a dry mouth (no saliva). if he has wet eyes and mouth you can just hang in there a bit longer and see if increased fluids today will help. popsicles commercially-available electrolyte solutions jello ice chips etc. all can entice a toddler to hydrate. main concern is no appetite lips are blistering not drinking much. plays for a few minutes and then just falls asleep. very unusual for her.
19 mo. old had a 102 degree fever friday but seemed to break it with meds-now isn't urinating normal-no bw mvmt 2 dys. he had wet diapers yesterday but not as frequent as normal. his diaper this morning was dry and clean which is very abnormal. he hasn't had a bowel movement since friday. he was drinking milk all day yesterday but wouldn't eat anything substantial. he acts fine just kind of sporatic cranky. his belly and back don't seem to be sensitive or in pain.