Good Morning and welcome. I am Dr. Loretta, a licensed veterinarian and I am happy to answer your question.
It appears to me that Calvin has a mild digestive disturbance caused by possibly the hypoglycemic episode. This causes loose stool that irritates the very sensitive rectal mucosa which causes small blood vessels to break and bleed. The Mucous is present because Calvin is in pain and the stool has remained in the colon too long.
This also could be caused by Coccidia, Coronoavirus or parvovirus so , since Calvin is quite young, it is best to have him checked out again by your vet.
In the meantime, fast Calvin for 12 hrs and at the same time, give him Pepcid AC at 0.5 mg per pound every 8 hrs. After the fast, feed Calvin a small meal of rice and chicken....if he is feeling better and the stool is normal, then he will be fine.
If he is still having trouble, take Calvin to your vet right away....even the dehydration can cause Calvin serious complications.
Does that make sense to you?
Please let me know if you have ANY other questions. My goal is to give you 100% satisfaction and if you are not yet satisfied, please Reply so I can clarify for you
Sincerely, XXXXX XXXXX