question for MSPI moms

3litttlebirds

DS is 16 weeks old, 10 weeks adjusted. He is EBF. Up until recently, his poops were always the normal yellow color, seedy in texture, and he would have a bowel movement 2-3x per day. At the beginning of this month, I noticed brown flecks in his poop. Testing at the peds showed blood in his poop. No other symptoms other than the blood. No fussiness associated with meals or pooping, no refusing to eat. Ped suggested to cut out dairy due to the blood.

So I've been dairy free for about 3 weeks now. Last week, he all of a sudden went 4 days without pooping at all. During that time, he had more gas and it was very smelly. When he finally did poop, it was brown with mucus, and with no real solidity to it other than the mucus...in other words, nothing on the surface of the diaper other than the mucus, everything else soaked into the diaper. He went another 3 days without pooping and again it was the same, brown with mucus. Also, I can't decide if the mucus looks reddish tinted or not. No fever, no other symptoms.

On-call nurse at the peds was no help. Just said brown poop can be normal and actually suggested to give him glycerine suppositories to get him to poop more often.

My question is....if it were a dairy allergy, shouldn't it be getting somewhat better by now (after 3 weeks)? I'm wondering if he has a nut allergy instead, as since I've cut out dairy, I've had a lot of almond milk and peanut butter sandwiches. Also, it's worth mentioning that I am on antibiotics for mastitis...not sure if that's what could be changing his poops right now.

Any thoughts?