A 2-week-old baby who has not pooped for 4 days may be caused by physiologic reasons and can be left untreated. It may also be due to intestinal obstruction, constipation, etc., which can be treated by gastrointestinal decompression, medication or surgery. 1. Physiological reasons: 2-week-old baby 4 days no poop may be due to a small amount of milk due to the phenomenon does not require special treatment, parents can appropriately increase the baby’s milk intake, and at the same time to the abdomen for clockwise kneading, to promote peristalsis, to help defecation. 2. Intestinal obstruction: Intestinal obstruction can also cause the baby 4 days without stool. At this time, gastrointestinal decompression, correct hydroelectric disorders, anti-infection and surgical treatment. 3. constipation: 2 weeks old baby 4 days no stool need to consider the possibility of constipation, parents can give the baby a moderate amount of warm water to drink, increase intestinal moisture, if necessary, you can take probiotics to regulate the intestinal flora, such as bifidus triple bacterial powder. If the stool is more dry, you can use Kesler to help defecate. There are many other reasons for a 2-week-old baby not having a bowel movement for 4 days, such as intussusception, toxic intestinal paralysis, congenital megacolon, etc. Parents are advised to take their babies to the hospital in time for diagnosis and treatment. If you need to use the above drugs, you need to use under the guidance of a doctor, avoid self-medication.