“Health care providers often classify ulcerative colitis according to its location being the types of ulcerative colitis the patient has. Symptoms of each type often overlap. Types of ulcerative colitis include:

• Ulcerative proctitis. Inflammation is confined to the area closest to the anus, also called the rectum. Rectal bleeding may be the only sign of the disease.
• Proctosigmoiditis. Inflammation involves the rectum and sigmoid colon — the lower end of the colon. Symptoms include bloody diarrhea, abdominal cramps and pain, and an inability to move the bowels despite the urge to do so. This is called tenesmus.
• Left-sided colitis. Inflammation extends from the rectum up through the sigmoid and descending portions of the colon. Symptoms include bloody diarrhea, abdominal cramping and pain on the left side, and urgency to defecate.
• Pancolitis. This type often affects the entire colon and causes bouts of bloody diarrhea that may be severe, abdominal cramps and pain, fatigue, and significant weight loss.”

MAYO CLINIC (https://www.mayoclinic.org/diseases-conditions/ulcerative-colitis/symptoms-causes/syc-20353326)

” One of the main differences between ulcerative colitis and Crohn’s disease are: Ulcerative colitis is limited to the colon while Crohn’s disease can occur anywhere between the mouth and the anus. In Crohn’s disease, there are healthy parts of the intestine mixed in between inflamed areas.  Ulcerative colitis and Crohn’s disease are the two main forms of inflammatory bowel diseases. They are both conditions characterized by chronic inflammation of the digestive tract. Although they share many similarities, there are key differences between the two diseases.”

UCLS Health (https://www.uclahealth.org/medical-services/gastro/ibd/what-ibd/ulcerative-colitis-vs-crohns-disease)