An anal fissure occurs when a piece of stool that is too big for the anal canal to take tries to force its way down the canal and in effect damages its tissues. The damages inflicted by the large stool cause painful sensations in future bowel movements, which develop into anal fissures. This condition can be diagnosed by a rectal exam and a person can ask a medical professional about its symptoms, as well as its causes. One of the ongoing theories that people have regarding the origins of the condition is that medical marijuana and other drugs such as cocaine can cause it. The relation between the two has never been studied in depth, and there is only a very few researches available on the topic, which only aggravates the question: are drugs (Cocaine, Cannabis, Marijuana) responsible for anal fissures?
The only sure answer to this question is no. Drugs such as cocaine and marijuana do not actually directly cause anal fissures. Anal fissures actually occur as a result of the body’s physical response to something that it is unable to process. When we think of the reason why anal fissures exist, we must remember that the anal canal where the bowels pass is not the most flexible area of the body we have, and can only stretch to a certain extent. When it has exceeded its capacity, controlling a large amount of bowel and forcing it out of the body can cause strain to the canal, which leads to spasm of the muscles in the anal canal and damages to it, culminating to the formation of anal fissures or hemorrhoids. An indirect factor that can affect the spasm of the anal canal is stress, although this seldom happens.
As to the case of drugs, there is almost no existing proof that it causes anal fissures. However, it is actually being used to treat them. Many pot smokers, as well as some medical professionals, believe that smoking pot can actually help reduce the risk of anal canal spasms, which leads to anal fissures. Since marijuana has calming properties, the drug actually aids in keeping the spasm of the anal canal away. If the spasms stop, the likelihood of developing anal fissures drop.
However, medical professionals commonly warn against the use of cannabis or cocaine when reducing the risk of anal fissure or any medical condition in general. Given that both drugs are still not legal in some parts of the world, purchasing and using them can be considered as against the law. Secondly, people do not always respond to the use of cannabis in a positive way. Some people, specifically those who do not smoke at all, may find it difficult to smoke pot and may even develop coughs and sore throats. Another side effect, of course, is getting high. Getting high on pot can be a good thing or a bad thing, depending on what you actually aim to do with the drug.
So, to conclude and to answer the question are drugs (Cocaine, Cannabis, Marijuana) responsible for anal fissures, as of this moment when few information is available to come up with something that can support this claim, the answer would be a definite no.