Behavioral-related
Lack of exercise
Diet-related
Fecal impaction
Stercoral colitis
Diverticulitis
Bowel obstruction
Small bowel obstruction
Large bowel obstruction
Ogilvie's syndrome
Malignant bowel obstruction
Specific causes: tumor, stricture, hernia, adhesion, volvulus
Painful anorectal disorders (e.g. anal fissure, hemorrhoids)
Medical causes
Hypothyroidism 
Electrolytes
Hypomagnesia
Hypercalcemia
Hypokalemia
Medication-related
Opiods, antipsychotics, anticholinergics, antacid, antihistamines<unk>  (peds)
Lack of exercise
Diet-related
Small bowel obstruction
Large bowel obstruction
Ogilvie's syndrome
Malignant bowel obstruction
Specific causes: tumor, stricture, hernia, adhesion, volvulus
Ogilvie's syndrome
Hypothyroidism 
Electrolytes
Hypomagnesia
Hypercalcemia
Hypokalemia
Hypomagnesia
Hypercalcemia
Opiods, antipsychotics, anticholinergics, antacid, antihistamines
Anal fissure
Anal fistula
Anal malignancy
Anal tags
Anorectal abscess
Colorectal malignancy
Condyloma acuminata<unk> 
Crohn's disease
Cryptitis
GC/Chlamydia
Hemorrhoids
Internal hemorrhoid
External hemorrhoid
Pedunculated polyp
Pilonidal cyst
Proctitis
Pruritus ani
Rectal foreign body
Rectal prolapse
Syphilitic fissure
Internal hemorrhoid
External hemorrhoid
Obesity
Intestinal obstruction
Pregnancy
Ascites
Cirrhosis
Malignancy
Heart failure
Tuberculosis
Spontaneous bacterial peritonitis
Peritoneal dialysis-associated peritonitis
Distended bladder / Acute urinary retention<unk>  / fecal impaction
Large tumor(s) (e.g. ovarian, lymphoma)
Organomegaly
Cirrhosis
Malignancy
Heart failure
Tuberculosis
Constipation
Behavioral-related
Dysuria
Lack of exercise
Dysphagia
Diet-related
Hiccups
Fecal impaction