Diarrhea and colic under the navel may be caused by food poisoning, ulcerative colitis, Crohn’s disease and other diseases. 1. Food poisoning: the cause of the disease is eating food containing toxic substances, such as Salmonella spp, Escherichia coli, staphylococcus and chemical poisons. If it is gastrointestinal food poisoning, patients will have nausea, vomiting, diarrhea, abdominal pain and other symptoms, mostly manifested as paroxysmal colic, mostly seen in the umbilical region or the upper abdomen. 2. Ulcerative colitis: the etiology of this disease is not yet clear, it is currently believed to be related to genetics, intestinal micro-ecology, immune dysfunction and other factors, which can be triggered by climate change, dietary impurity and other factors. Patients will experience abdominal pain, diarrhea and other symptoms, and some patients may experience colic under the navel. 3. Crohn’s disease: the occurrence of this disease is genetic, environmental, immune, intestinal flora dysbiosis, pathogenic microbial infection and other factors interacting with the results, the typical symptoms are abdominal pain, diarrhea, etc., can be manifested as colic under the navel. It is recommended that patients with diarrhea and cramps under the navel go to the hospital in time to complete the relevant examinations and identify the specific causes under the guidance of professional physicians.