This is a specific response.
In the section on “Botulism” in The Merck Manual of Medical Information, page 565, it says: “Botulism is an uncommon, life-threatening poisoning caused by the toxins produced by the bacterium Clostridium botulinum.”
“Infant botulism, which also results from ingesting contaminated food, occurs in infants.”
On page 566 it says: “Infant botulism occurs most frequently in babies who are 2 to 3 months old. Unlike foodborne botulism, infant botulism isn’t caused by swallowing a previously formed toxin. It results from eating food containing spores, which then grow in the baby’s intestine and produce a toxin. The cause of most cases isn’t known, but some cases have been linked to the ingestion of honey. Clostridium botulinum is common in the environment, and many cases may result from the ingestion of small amounts of dust or soil.
Under the heading “Symptoms” it says: “In about two thirds of the babies with infant botulism, constipation is the first symptom. Then paralysis of the nerves and muscles develops, beginning in the face and head and eventually reaching the arms, legs, and breathing muscles. The nerves on one side of the body may be damaged more than those on the other side. Problems range from mild lethargy and prolonged feeding time to severe loss of muscle tone and an inability to breathe properly.
Under the heading “Diagnosis” it says: “Finding the bacterium or its toxin in a sample of a baby’s feces confirms the diagnosis of infant botulism.”