This happens every now and then where I take a sh*t or something and I get strong burning in the tip of penis and anus. This started happening out of nowhere, I drink plenty of water and I avoid spicy foods. Everyday I do everything very similarly so I am unsure of why this is happening. I have never had any sex diseases or infections and have never had sex. I have tried washing the area but nothing helps and it is quite annoying having this problem occur at least once a week. 

I have suspicions that it is either because of the strong smell coming from the sh*t and piss in the toilet since when I take a sh*t, circumcised penis dangles slightly pointing down in the bowl but not touching anything. Note that I do share the toilet in my house with another so let me know if it might be something to do with that. This has been going on for a few months and I am too embarrassed to consult a doctor, I would appreciate any help and would like to know the cause of the problem. Thanks in advance for any responses.