First of all, there is not quite enough info to accurately answer your question. What do you mean when you say you have a problem going to the bathroom? Are you overweight? If so, by how much? Do you have a fat pad on your pubic region? What do you consider small?
Hello. We suggest you speak to your doctor about this and work on a plan to improve this. Here is an article to help you https://www.healthline.com/health/buried-penis Things that make this more likely are excess fat, fluid retention, problems with ligaments, and complications after a circumcision. Other causes include Too much or not enough foreskin is removed during circumcision. The remaining skin around the penis may be pulled forward, hiding the penis.
The ligaments that attach the penis to the body are abnormally weak.
Swelling of the scrotum caused by a buildup of lymph fluid (lymphedema) can bury the penis.
Excessive fat in a male who is obese may cover the penis.
If you work to treat the reasons for why you have this condition, you could have a profound effect on any urinary or sexual difficulties you may have. Please speak to your doctor.