Acute lower central (hypogastric) abdominal pain

Some differential diagnoses and typical outline evidence

Infective or ulcerative colitis	Suggested by: abdominal pain, diarrhoea with blood and mucus.
	Confirmed by: stool microscopy and culture, colonoscopy.
	Management: OHCM pp218–19, 244–5.
Large bowel obstruction	Suggested by: severe distension, late vomiting, visible peristalsis, resonant percussion, increased bowel sounds. Supine AXR showing peripheral abdominal large bowel shadow (with haustra partly crossing the lumen). Fluid levels on erect film.
	Confirmed by: abdominal ultrasound and laparotomy findings.
	Management: OHCM p492.
Cystitis	Suggested by: frequency, urgency, dysuria, ± haematuria.
	Confirmed by: MSUfor microscopy and culture.
	Management: OHCS p262.
Pelvic inflammatory disease	Suggested by: vaginal discharge, dysuria, dyspareunia, pelvic tenderness on moving cervix, ↑ ESR and CRP. WBC: leucocytosis.
	Confirmed by: High vaginal swab, pelvic ultrasound, ± laparoscopy.
	Management: OHCS p286.
Pelvic endometriosis	Suggested by: dysmenorrhoea, ovulation pain, dyspareunia, infertility, pelvic mass.
	Confirmed by: laparoscopy.
	Management: OHCS p288.
Ectopic pregnancy	Suggested by: constant unilateral pain ± referred shoulder pain, amenorrhoea, vaginal bleeding (usually less than normal period), faintness with an acute rupture.
	Confirmed by: pregnancy test +ve, bimanual examination reveals slightly enlarged uterus, pelvic ultrasound shows empty uterus with thickened decidua.
	Management: OHCS p262–3.