Safe parasite cleanse for ill 4 year old child

My four year old has had some unanswered health concerns since he was a baby. He has a constant sinus issue. Thick green mucus that doesn't clear up. His poor tummy is always upset. He has diarrhea or loose stool multiple times a day and sometimes wakes up with diarrhea. He has to go after he eats anything. His glands in his neck are always enlarged. He recently started bedwetting again and grinding his teeth at night. He cannot sleep thru the night. He also has low energy. He has had his blood drawn and many tests ran over the years and was even hospitalized for a strange rash. All the tests come back normal and the Drs say he's fine. He has a very normal routine with nothing new or stressful. Something is not right. I want to try a parasite cleanse but I'm new to the concept. Can anyone recommend a safe cleanse for a child or any suggestions.