I figured I'd trot this old one out again:
Once there was a Native American named Bowell. He got a letter one day from the Bureau of Indian Affairs saying he would have to move his teepee to a new reservation. Angered, he marched down to the Indian agent's office, knocked on his door, and stamped inside.
"Bowell no move!" he said in a commanding voice. The Indian agent nodded, and said, "Go next door, they'll fix you up."
So Bowell went to the next office, which was the the doctor's in charge of reservation health care.
"Bowell no move!"
"OK, here, take one of these once a day, then come back in a week," the sawbones said, handing Bowell a bottle of pills.
A week later Bowell marched into the doctor's office and snapped, "Bowell no move!" The doctor seemed surprised, but gave him a bottle of larger pills. "Take two of those a day, and see me in another week."
A week passed, and Bowell presented himself in the doctor's office again. "Bowell no move!!" he thundered. The doctor scratched his head, then handed Bowell a bottle of gigantic horse pills. "There, take five of those a day, and see me next week."
A week later Bowell showed up at the doctor's office again. Before he could say anything, the doctor said, "Let me guess. Bowel no move?"
And Bowell said, "Bowell gotta move. Teepee full of shit."