I had a bowel obstruction that lasted six days. It was the most physically agonizing experience of my life. It was brought on by too little food (HCG diet) coupled with too little water AND too many whole sunflower seeds. I thought I could continue munching whole sunflower seeds as I did when I was on a normal diet. Sunflower seeds became a much larger portion of my diet and I caused my bowel to get obstructed.
Day three post recovery and I still have symptoms and my appetite has not fully returned. Which is OK because the silver lining to this story is that I got my weight under 240 once more.