Dr. Sebastian Zavoian, MD

No, a polypectomy is not painful.

"Bleeding from bottom" can be caused by a number of problems, from relatively simple ones such as a mucosal tear, to more complex chronic diseases. Typically, this type of problem would require at least talking to your primary provider, likely being examined, and possibly having testing done. Tight pants are unlikely to cause bleeding.

While symptoms such as diarrhea, abdominal pain, and weight loss can increase a suspicion for Crohn's disease, we always work with a list of differentials or possible diagnoses. In general, we may have to consider an infection, or other chronic diseases such as celiac disease. Most of the time, a diagnosis of Crohn's disease will require a combination of testing studies, including blood work, likely EGD (upper endoscopy) and colonoscopy, usually some stool studies, imaging of the abdomen such as a CT scan or an MRI. This is best planned under the care of a pediatric GI specialist. Some initial work up can be done under the care of the primary care provider as well, as warranted. As you are waiting to see your primary provider or a specialist, I would recommend making sure your son stays well hydrated, continues to eat as balanced as possible, avoiding processed foods, and avoiding foods with lots of carbs or sugar. A diet similar to the Mediterranean is probably the healthiest in general and it would help even if inflammation in the intestine would turn out to be the problem. This means eating meals cooked with whole ingredients, especially plants, fruits, veggies, etc. I would avoid most foods that are packaged and processed at a plant (such as chips, cookies, processed snacks, even fast food). I recommend drinking water as much as possible, consider avoiding lactose-containing dairy, and avoid very sugary or sweet drinks, even if they are labeled "diet." If the pain gets severe, we alway recommend immediate evaluation, either by the primary care provider or at an urgent care or emergency room. The same if the child looks ill, very tired, which can happen if the diarrhea becomes severe and the child is unable to eat or drink fluids.
Hope your son will feel better soon and please do not hesitate to have him evaluated, probably first by his primary care provider.