Most of the symptoms of botulism are digestive in nature. The reason for this is in most cases the bacteria enters the body through the mouth. Constipation may occur because botulism will first attack the esophagus. As the bacteria attack the esophagus it causes the entire digestive process to malfunction. In fact, a person suffering from constipation may not even have the slightest hint of a stool.
The malfunction of the digestive system means that the food that you eat is not being converted into nutrients and waste. If you have noticed that you are not having normal bowel movements and you are taking laxatives and probiotics and they do not help, it is a good idea to visit a doctor. Constipation is one of the first and quickest symptoms to come up, so if you catch it early the healing and the treatment process can be much easier.