I have had an abdominal pain, diarrhea, headache,...

Dear Customer
Evaluating the answer from the top of the page after reading it helps us to improve the quality of answers and ensure that the best experts are available to help you .

what is the treatment of chronic constipation ?

1. drinking water as much as you can  ( warm ) 
2. healthy diet , prepared at home and having regular meals time 
3. a diet rich with fibers 
4. vitmian C juice such as lemon or apple juice 
5. there is some medication to increase intestine motlity such as laxutives 
6. in case of gastrointestinal infection , doctor may prescribe some antibiotics such as flagyl beside pain killer medications such as ibuprofen 
7. if there is a serious medical issue the effect your gastic system , its should be treated first because constipation is a secondary symptom .

causes of constipation : 

1. poor diet generally with lacking of fibers 
2. drinking small amount of water 
3. gastic system infections 
4. serious gastic diseases 
5. intestine obstruction
6. peptic ulcers and internal bleeding 

required medical checks : 

1. clinical medical check by specialist doctor ( internal medicine ) 
2. blood and kidney test 
3. urine and stool test 
4. endoscopy for internal intestiine 
5. abodminal CT scan 

our advice : 

its more likely to have GI infection , so we strongly advise you to follow our advices and consult an internal medicine doctor to do the needed medical examnation and determine the treatment pathway
You can also ask our other certified experts in various fields such as: Nutritionists, Lawyers, IT Experts, Therapists, Mechanics, Doctors, Handymen, and more.
Kind Regards