“Can anesthesia cause constipation?”

Yes, if opioids are used

Pain, dehydration and opiates are the main cause of constipation post operation. All medication and other causes should always be taken into consideration.

This brings up a good discussion of anesthesia, and probably a broader discussion than what your question intended. The answer may be confusing on the surface, because the answer is No, Yes, and Maybe. Here's the deeper explanation: "anesthesia" is made up of many different pharmacologic agents that can be administered to the body in different ways. for a few broad, general categories, those ways may be local anesthesia, regional anesthesia (i.e. "nerve blocks"), or general anesthesia. Within each of those broad categories of anesthesia, there can be many different medications used to accomplish each of those categories of anesthesia. For instance, there are many different drugs that can be selected to provide local anesthesia or nerve blocks. Often, the specific medication or group of medications selected depends on the duration of loss of sensation that is desired for the procedure, or a specific medication may be selected to avoid specific medication effects or side-effects. Likewise, when selecting medications for general anesthesia, resulting in complete unconsciousness, there are many different medications that may be selected, or even a "blend" of those medications may be selected. Within that "blend" it is certainly clearly recognized that some medications which either cause general anesthesia by themselves at the right dose, or contribute to general anesthesia when mixed with other medications with anesthesia properties, have a side-effect of promoting the effects of constipation. The most obvious of these medications where constipation tends to be a "side-effect" is whenever any opioid medication is used. These opioid medications are often referred to as "narcotics". But there are many other medications that are not anesthesia agents that also tend to cause constipation. Essentially any medication that encourages more water absorption into the body from the contents inside the intestine tends to promote constipation. Since all "narcotics" tend to slow the transit time through the intestine, it gives more time for water to be absorbed from whatever is inside the intestine. A greater amount of water absorption results in a material moving through with less remaining fluid. Less remain fluid in that mass, makes it more difficult to pass that mass through the intestine and completely out of the body. This is what is recognized as "constipation".

Yes, general anesthesia can cause constipation. You need good hydration and may sometimes need stool softener for a few days.

Yes. Due to muscular relaxants and paralisis of the gouts